Tools for 3rg gen Prius.

Pan plug is 14mm
Keep the car level....especially when filling.
You will need oil, filter, filter O-ring,filter removal tool,and plug gasket.
Strong hand tighten everything.

 

Keep it level.

 

The oil filter socket requires a 14-face socket with 64 mm inside face-to-face dimension.

Torque specs:

Oil pan drain bolt: 27 (ft/lb)
Filter: 18
(the Toyota filter comes comeplete with replacement O-Ring)

There's no need to keep the car level during the drain. I would just button up, lower the car, and put in the spec'd quantity of oil.

When checking oil level, then obviously it's best if the car's level. it's best to remove the dipstick, wipe it, and wait a few minutes before reinserting for the check. Oil tends to hang in the dipstick tube, the wait gives it time to drain down.

 

How to videos:
Nutz About Bolts Prius Maintenance Videos | PriusChat

 

It's my mission in life to talk you into changing your transmission fluid, your air filter, and lubricating your brake caliper pins. Come on, join the club!

With that said:
If you have a decent cement garage or flat driveway area, I think jack + jack stands are better than ramps for several reasons:
1) More versatile; more types of repairs can be made (like fix a flat tire).
2) Driving up ramps takes a second person
3) Prius bumper scrapes ramp as you ascend
4) Take up a ton of garage space

I've had cheap floor jack, then ramps, and now pro floor jack. The ramps are pretty "meh," but some prefer them and that's cool.

For tools, you can see the minimum but I recommend a Sears Craftsman set priced on sale at about $100. Get one that comes in a fitted case, so when you're done, you can quickly tell if you've got all your sockets. I'd be happy to help you pick out a set that's on sale and appropriate. There are other miscellaneous tools you'll need, namely the oil filter wrench, big funnel, nitrile gloves and drain pan.