The only thing you need to be aware of is that the settling may not be done. So, if it's not, and you repair the cracks now, you'll only be back doing it again - maybe in relatively short order.
Depending on the size of the crack, you may get away with just laying in some joint compount. If they're 'large' cracks, you'll need some joint tape. What you want to do, since this is new to you, is either go to a book store or to a Home Center, and look for a book (or chapter) that talks about hanging drywall. Part of this 'project' involves doing seams. Better yet, look for a section that talks about drywall repair. (Repair books are better at describing this than 'construction books'. Construction books are for 'hanging and finishing' drywall; not necessarily 'repairing' them.) The few $$$ you spend on this is a LOT less $$$ than you'd spend on a pro coming to the house.
Time-Life and Reader's Digest have good series on Home Repairs. If you do this job right, you'll be doing basic plumbing too, and more! When you're satisfied with the repair job, clean the area well and apply 2 coats of Primer/Sealer before you paint. To see how well you did your job (before painting), get the room real dark and hold a lamp a short distance away from the crack up against the wall. Look for 'shadows'. If you see any, you have too much compound on the wall. You may need to sand some more. YOu can sand and add compound and sand and add compound 'till the cows come home so don't worry about mistakes. If you're painting, got to a local Paint Retailer (listed in the Yellow Pages under PAINT REATIL) and get your Primer/Sealer there along with your Finish Paint and supplies. They'll be able to help you with any questions you have too! (They're help is free too!)