Tools:
Hydralic Jack-I prefer to use a truck jack for cars, because they give you more lift
2x Jack Stands -never work under your car without using them
Socket Wrench + Socket-socket size varies by car, I reccomend using 6 point sockets, because you don't want to strip the bolt in the oil pan
Cardboard-helps you slide better
Funnel-you don't want to spill that oil all over the engine bay
Paper Towels-to clean the dipstick
Oil Filter Tool-when you get the oil filter at the store open the box and see which tool fits best.
Container to catch oil
Supplies
Oil-look into your car manual and find out how many quarts you'll need, also find out which version of oil you need...i.e. 5W30, 5W20 etc. Then go to autozone/pepboys and buy some. There are conventional and synthetic oils...main difference is one lasts longer and is somewhat better...but costs more(sometimes 2x). So I would only use synthetic on a good car.
Oil Filter-in the oil department, you'll see a big manual...about 600 pages long...in it you'll have to find your car and find the part # for the oil filter.
Now we have all the supplies, time to start working