If you have to ask what tools are needed, then perhaps you're already in over your head. We're talking about keeping water out of the house here!
I'm not trying to rain on your parade but that's exactly what might happen if you don't do this job right. This job takes some skill which isn't exacly 'expressed' in your post. SO, I'll do better than you'd think. There are PLENTY of books out there that you can buy, or borrow from the library, on how to do a roof. For the $$$ you'd save on having a pro do it, you might as well show some forthought in spending some of that savings on some literature. There are a LOT of things you didn't mention here that are of importance in answering your post.
Do you have a hip roof? Will you need to install chimney flashing? How many layers of shingles do you already have? What do the layer(s) of existing shingles consist of? What do YOU want to install for new shingles? Do you have a ridge vent? Is there drip edge on the roof now? (Please don't answer them; they're mainly for your benefit to answer because you'll need to know them in order to do this job.)
One thing you ought to consider doing anyway is getting an estimate or 2. You'd be surprised at how inexpensive it is to do a roof, and for the price you get, you just may opt not to make a go at it yourself. As with a lot of things in life, there are right and wrong ways to do this job as well as there are tricks in doing it. Again, buy yourself some literature. At least you'll see what you're in for.
Now, if you're going to go with fiberglass shingles and your folks plan on staying around a while, I'd get a 30 year shingle. If you have soffit vents and don't have a ridge vent, I'd have a ridge vent put in. Drip edge is necessary if you don't have it. DON'T skimp on the nails or the tar paper. Since you don't know what you're doing, you'll need multi-story ladders, 2 ladder jacks, and a skif. My best to ya and hope this helps.