A pretty standard projection format is a basic "Marcel the Monkey" technique. It takes three years of prior statistics and takes a weighted average of those three years, with the weights being 50% for the prior season, 33% for two years prior, and 17% for three years prior. Obviously you'd have to normalize the ABs per season and adjust the actual counting stats. This is a very rudimentary system and I wouldn't recommend you actually use the data you get, as there are lots of free projection sets out there that do a much better job (Chone, ZiPS, etc) but for your school project, this should be fairly easy to do. If you need something more advanced (not sure the level you're at) you can break down and deal with the stats individually and take into account how the age of each player affects each category. There's lots of data out there to guide you on this if you're interested. It's good to get familiar with Excel too, because in my years of college doing economics and now chemistry, the most use I've found with Excel is fantasy baseball. What point is there in using regressions and standard deviations and blah blah blah if it can't be applied to something fun? Good luck!