Dr. Peres has started an Archaeology Field School Toolkit Listmania on Amazon. Some of these are required for the students in the MTSU Archaeology Field School (sunscreen!), and some are tried & true.
You can see the full list here: Archaeology Field School Toolkit
What recommendations do you have for students just starting out in archaeology (and on a limited budget)? Not limited to equipment, advice, tips, and tricks are all welcome (as long as they are legal, safe, and sane). Post your recs/advice in the comments!