Reddit mentions of Dungeon & Dragons: Dungeon Master's Guide - Roleplaying Game Core Rules, 4th Edition

First, I'd recommend that you keep the box and all of the components in good condition, so you can consider re-selling it once you're done with it. The Red Box seems to be out of print and is selling for far above its $20 MSRP, and if you can recoup some of the money you spent on it to buy some resources that will have more lasting value, it might be worth it (depending on how highly you value your time), since you will have little use for most of the contents of the box once you're through with the initial adventure.

Or, if it's not too late, you may want to cancel your order. The Starter Set is a relatively gentle introduction to D&D, but not necessarily the best one and certainly not the cheapest.

To prepare, you might want to read, and have everyone else read, the quick start rules. You can also have the players choose pre-generated characters from that document and print off the corresponding character sheets. The Red Box method of character creation involves running through a solo "choose-your-own-adventure" book, which you might not want to do 3 or 4 times in succession for each of your players. Note that the the quick start rules uses slightly different versions of the character classes presented in the Red Box, but the characters/systems are compatible.

You will not immediately need to create your own group adventure, as one is included with the Starter Set.

Also, as an alternative to the Starter Set, /u/Dracoprimus posted a bunch of links to free adventures. You can also choose to run one of these adventures after you finish with the Red Box.

However, neither those those links nor the Red Box will not give you the resources needed to build your own characters or advance them past level 2, nor do they contain the info a DM needs to create his own campaign, or extensively modify an existing one. For that, I recommend getting the following resources (buying some of the books used may yield a good savings):

• Heroes of the Fallen Lands (alternatives/supplements: Heroes of the Forgotten Kingdoms, the 4e Player's Handbook)
  
• The 4e Dungeon Master's Guide (alternative/supplement: the 4e Rules Compendium)
  
• The Monster Vault (buy a new or like-new copy so you can be sure you get all of the included components)
  
  With those three products, you have everything you need to run a level 1-30 campaign. A D&D Insider subscription can substitute for those resources to a large extent, and supplement them with tons of content, but it's most useful as a convenience and reference. I would still recommend getting the core books even if your group has a DDI sub.
  
  On top of that, a few game aids are nice to have:
  
  
• A blank, reusable flip-mat, like the Paizo basic flip-mat, plus some dry- or wet-erase markers.
  
• Alternatively, a 1" gridded easel pad, which you can probably get at an office supply store.
  
• Enough dice for everyone. Bulk dice like Chessex Pound O' Dice can be a good way to go.
  
• Tokens or character markers. The Monster Vault and Starter Set include some. You can make your own, buy miniatures or products that come with miniatures, like the Descent board game or the Legend of Drizzt, or WotC's Dungeon Command games.

If you are really serious about learning and wanting to play D&D, I would strongly advise getting the 4th Edition Player's Handbook. Then after that I would suggest getting the Dungeon Master's Manual.

There are a ton of places online where you can download PDF copies of the books if you don't feel like shelling out the money for it.

Once you have a copy, read it, cover to cover. If you find yourself reading through it quickly, you know you are getting into the right hobby for you.

Understand that all play groups are different. Some are more relaxed when it comes to the rules, and care more about the role-playing aspect of the game. Others are rule nazis, and make sure that the game is played to the T. You need to find the right balance for you to make the hobby interesting.

What is most important to make D&D work is to have a thoughtful Dungeon Master(DM). One that is able to control the group, have an average to above average understanding of the game, and make for a fun experience.

If you have any more questions, PM me. I live in Atlantic County, about a 45 min drive to Tom's River, but I might be able to help you out.

EDIT** This goes for everyone in this thread that are stating that they are new and want to play. Let me know and maybe I can start to organize something, I don't mind teaching new people 4E rules.

If you are planning on playing 4e with a group of non-gamers, go for the Red Box since it's relatively cheap and is designed for non-gamers. It's not the complete version of the game, it's a tutorial adventure to teach players some core concepts .

If you decide to go with the full game, you need the Players Handbook, Dungeon Master's Guide, and Monster Manual. These are three separate books. There are other volumes to each of these (for example PHB II) but you don't need them.

There's also an online subscription called D&D Insider that I've never used, but it seems like about 50% of people find it invaluable and the other 50% call it a racket.

Downsides to switching are well covered in this thread. Personally I found 4e to be so oriented towards combat that every other part of the game suffered. It felt like everything except the tactical combat module had been tacked on half-heartedly.

But this is after 20 years of playing older editions of D&D, so I may just be predisposed against the design changes they made in a way that newer players won't be. You may love it, and that's all that matters.

I think the better question though is what are your reasons for choosing D&D? Is there something about the system that makes you think you'll like it? What are you looking for? What did you like and dislike about Pathfinder? There are literally hundreds of other systems out there, you may want to look around at some of them, and I know /r/rpg loves to give recommendations if you want them to.

This depends on what type of D&D you want to play. I play 4e. From my understanding of previous editions, much more of 4e happens on the table. If you have experience with tabletop games like I, and my friends, had, you should try this out. If not, it's very easy to pick up.

I'm pretty sure that Spencer is DMing a Pathfinder game in the podcast. It's definitely 3.5.

Anyway, back to the starting point. If you're interested in trying 4e, skip the starter set. It's useless. It gives you enough information to get 4 classes to level 2, and incorrectly at that. The provided adventure is boring, and you're not left with a whole lot to do after that.

If you're looking for the cheapest game possible, you'll need:

Players Handbook 1 http://www.amazon.com/Dungeons-Dragons-Players-Handbook-Roleplaying/dp/0786948671/ref=sr_1_1?s=books&ie=UTF8&qid=1381660555&sr=1-1&keywords=4e+players+handbook

Monster Manual 1 http://www.amazon.com/Dungeons-Dragons-Monster-Manual-Roleplaying/dp/0786948523/ref=sr_1_1?s=books&ie=UTF8&qid=1381660601&sr=1-1&keywords=4e+monster+manual

Core Rulebook http://www.amazon.com/Dungeons-Dragons-Dungeon-Masters-Guide/dp/0786948809/ref=pd_bxgy_b_img_y

If you want to play 4e correctly, these are the three books you need. Characters, maps, and monsters can be improvised as needed.

If you're willing to spend more, I would suggest this map:

http://www.amazon.com/Chessex-Role-Playing-Play-Mat/dp/B0015IQO2O/ref=sr_1_cc_1?s=aps&ie=UTF8&qid=1381660750&sr=1-1-catcorr&keywords=d%26d+vinyl+mat

With some wet erase markers (WET, not DRY), you can build any dungeon, castle, or moon colony you can imagine. Beyond those three books, I think this is the best investment you can make to immerse yourself and your friends into another world.

Wizards provides character sheets at the backs of some books, but there are better ones on their website for free.

https://www.wizards.com/dnd/Tool.aspx?x=dnd/4new/tool/charactersheet

Last, if you really want to make things as simple as possible, subscribe to D&D Insider.

http://www.wizards.com/dnd/tools.aspx

It's worth it for the character builder alone.

EDIT: Don't forget the dice!