I just got back from Peru to my home in the states 2 days ago!
If you like using a guidebook, Footprints is the only company I found that updates their South American guides annually. I also found all of the food recommendations I tried were fairly accurate, and their recommended highlights were solid (except for a few places in Cusco).
If you don't know Spanish, the Lonely Planet's Latin American phrasebook was pretty good and fit right in my backpocket. However, don't really stress out about it. Just do the "Coffee Break Spanish" podcast and go. Most Peruvians are friendly enough to try to communicate in English, or you can always pull out Google Translate.
I like great food, dancing/nightlife, and good trekking. My highlights: