Reddit mentions of Lonely Planet Italian Phrasebook & Dictionary (Phrasebooks)

I'm sure that plenty of people will disagree with me, but I REALLY don't like textbooks for self-study. It's always seemed to me that the authors of textbooks half-ass explaining things since they assume you'll have a teacher who can explain it to you. (Also they tend to be really expensive!)

For getting your feet underneath you, I honestly love phrasebooks (Rick Steves; Lonely Planet) and picture dictionaries.

At the start, I used (still use!) the "Practice Makes Perfect" series. They're not expensive at all, though they might as well be printed on newspaper - these are NOT long term reference works... there are a ton of these in the series that I haven't listed below, but these are good:

• Practice Makes Perfect Basic Italian
  
• Practice Makes Perfect Italian Vocabulary
  
• Practice Makes Perfect Italian Pronouns And Prepositions
  
• Practice Makes Perfect Italian Sentence Builder
  
• Practice Makes Perfect Italian Conversation
  
  These are more expensive but absolutely worth the price:
  
  
• Modern Italian Grammar: A Practical Guide (and the corresponding workbook maybe)
  
• Soluzioni: A Practical Grammar of Contemporary Italian
  
• A Reference Grammar of Modern Italian
  
• Using Italian: A Guide to Contemporary Usage
  
• Using Italian Vocabulary
  
• Using Italian Synonyms
  
  Edit: Forgot this one but it's worthwhile also - Italian Fluency: Twin-Words and Essential Vocabulary.
  
  Avoid at all costs ... "Italian for Dummies"; "501 Italian Verbs" :)

I would combine Duolingo, which is a fairly fun way to get a decent grasp on basic grammar and vocabulary, with a phrasebook geared specifically toward the type of conversations a tourist would likely have.

Edit: If you're already conversational in Spanish, which is a very similar language, you might surprise yourself with how much you'll learn in 20 minutes a day for two months. Of course you won't be fluent, but I don't think you'll have any problem reaching your goal.