Well, if you have your diet under control, then you shouldn't need much to put on a little lean muscle mass. I would say make sure you're sleeping 9 hours a night, but 8 would do. Also, for supplements, the ones you find on here are the best. Surge is what you should take postworkout (running or lifting) and Grow! is a great protein to have if you can't get in that mid-morning, mid-afternoon meal, and especially pre-bed.
However, if you have a really really tight budget and cannot afford them under any condition (nothing to sacrfice, such as going out to eat, buying "designer clothes", or anything to that extent), then you can find some whey hydrolysate(isolate is ok), maltodextrin, dextrose, bcaa's and mix them together. Sometimes the mixture might not taste the greatest, but it's better than it was even 5 years ago. Mixing your own ingredients will also consume some time every sunday, that's a usual thing though, just put them in plastic bags. Grow! is basically one of the cheapest low carb proteins you'll find on the net with the quality casein. However, if you cannot afford that either, I would say just use a whey concentrate, I did just fine off of that for about 1-2 years in high school.