Reddit mentions of Common Interior Alaska Cryptogams: Fungi, Lichenicolous Fungi, Lichenized Fungi, Slime Molds, Mosses, and Liverworts

Start by picking a guide for your area and reading it thoroughly, especially focusing on the anatomy of a mushroom. Go hunting a lot bringing back what you find, take spore prints and work though the IDs. Also joining a NAMA affiliated club will help tremendously.

Regional guides

Alaska

Common Interior Alaska Cryptogams

Western US

All The Rain Promises and More
Mushrooms of the Pacific Northwest

Midwestern US

Mushrooms of the Midwest

Edible Wild Mushrooms of Illinois and Surrounding States

Mushrooms of the Upper Midwest

Southern US

Texas Mushrooms: A Field Guide

Mushrooms of the Southeastern United States

Midwestern US

Mushrooms of the Midwest

Edible Wild Mushrooms of Illinois and Surrounding States

Mushrooms of the Upper Midwest

Eastern US

Mushrooms of West Virginia and the Central Appalachians

Mushrooms of Northeast North America (This was out of print for awhile but it's they're supposed to be reprinting so the price will be normal again)

Mushrooms of Northeastern North America

Macrofungi Associated with Oaks of Eastern North America(Macrofungi Associated with Oaks of Eastern North America)

Mushrooms of Cape Cod and the National Seashore

More specific guides

Psilocybin Mushrooms of the World

North American Boletes

Tricholomas of North America

Milk Mushrooms of North America

Waxcap Mushrooms of North America

Ascomycete of North America

Ascomycete in colour

Fungi of Switzerland: Vol. 1 Ascomycetes

PDFs

For Pholiotas

For Chlorophyllum

For parasitic fungi, Hypomyces etc "Mushrooms that Grow on other Mushrooms" by John Plischke. There's a free link to it somewhere but I cant find it.

Websites that aren't in the sidebar

For Amanita

For coprinoids

For Ascos

MycoQuebec: they have a kickass app but it's In French

Messiah college this has a lot of weird species for polypores and other things

Books that provide more info than field Mycology

The Kingdom of Fungi Excellent coffee table book has nice pictures and a breif guide to Fungal taxonomy and biology.

The Fifth Kingdom A bit more in depth

Introduction toFungi Textbook outlining metobolic, taxonomic and ecological roles of fungi. Need some level of biochemistry to have a grasp for this one but it's a good book to have.

I grew up in northwestern MD, so around the same area as you. I own and have used most of the guides folks here have mentioned. Most of them are good, but the guide I always find myself plopping in my basket is Mushrooms of West Virginia and the Central Appalachians by William Roody. The book itself is a little larger than other field guides (like Audubon's guide, for example), but the photos are MUCH larger and the descriptions of the mushrooms are informative without being overwhelming. I also found the layout of the book to be extremely intuitive.

Mushrooms Demystified is not a field guide. It is a large book and jam-packed with information. It is much more useful as an "after field guide" when you have your mushrooms at home and want to key them out. There a few color plates in the book but the book's real utility is in the identification keys for each genus.

I would also throw Mushrooms of Northeastern America as another "too big for the field" book. That book is massive. BUT, it is also the book I go to when I'm home from my mushroom hunting. It's a fantastic book to have.

All That the Rain Promises is a great little book. Very entertaining. But it's definitely a west coast guide.

I find the Audubon guide to have photos that are much too small to be very useful for at-a-glance ID in the field, and the breadth of material to be unnecessarily wide. The information contained within is definitely useful, but I have found other books that have a better layout and better pictures with the same or better information. The only real advantage it has over most other field guides is its size. If you're planning on shrooming around where you live, you're probably better off getting a guide for your specific region.

The Field Guide to the Wild Mushrooms of Pennsylvania And the Mid-atlantic is an alright book. All of the information it has is very good, but I did not find it to be comprehensive enough with the species it covered. Also, I hated the form factor of the guide itself (tall and skinny) because I could not keep it open by weighing down each side with a rock or just laying it on its spine, it had to be held open. I am someone who likes to fondle the mushrooms as I'm looking over the description in the guide, but it might not be the case with you. Just something to consider.

Edible Wild Mushrooms of North America: A Field-to-kitchen Guide is a great guide if you're out for edibles. It is not a good guide if you are out and want to identify everything you run across just for the fun of it. But with that in mind, I definitely would recommend it. I have only tried a few of the recipes myself, but they have all turned out well.

I agree that having good, clear photographs in a field guide is important - I'm a visual person and photos are the first thing I turn to when faced with an unfamiliar fungus. All that said, please remember that photos alone are not enough to positively identify a mushroom. They're great for getting a general idea of where to start, but they are not end-all be-all.

And as a last aside, a book that I picked up on a whim (just because I'm a bit of a mushroom book magpie) called Common Interior Alaska Cryptogams: Fungi, Lichenicolous Fungi, Lichenized Fungi, Slime Molds, Mosses, and Liverworts actually has (in my opinion) the best overview of mushroom physiological variations. There is a line drawing illustration of the character in question (for example, gill attachment) and then the terminology used to describe each variant of it. Other guides certainly have all of this information, but it is laid out in an incredibly elegant and intuitive way in this book. It helps a lot to know these things when working your way through keys.

Anyway, hope this was helpful!