I know how to check the basics, oil, coolant, but the brake fluid, tranny and diff fluid, want to make sure i'm doing it right. Diff fluid leaking and sprays of back window. Nice smell when it heats up (not)

 

Brake fluid is easy, open the hood, left side (assuming you are in the US) on the master cylinder is a little reservoir, look through it, there are lines, make sure it is full.
If not top off with DOT 3 brake fluid.
Brake fluid is corrosive so do not get it on your paint.
As for the trans, engine running, trans in park, using a allen wrench open the FILL plug on the front of the trans oil pan, trans fluid should come out of the hole, Dexron III is what it takes.
As for the diffs and t-case, remove the fill/check plug on the front diff, stick your finger in the hole straight, does it come out wet?
Yes? Its all good.
Same with the rear diff.
T-case is different, looking at the back of it you will see the parking brake drum, at the 10o'clock position is the fill/check plug, you will need a 1/2" drive ratchet to remove the plug, all you need is the ratchet or a breaker bar and maybe a extension.
The t-case and the diffs use gear oil.