how do i check my transmission fluid?

i got a 91 civic 1.5l dx hatch and i know you check the fluid level from a bolt that you undo, but which one and where? what is the best fluid if i were to drain the whole thing and refill it? i heard royal purple was the best. my gears crunch no matter what when i shift from 2nd to 3rd slightly. thanks!

the bolts on the passenger side...there's two of em on top of each other I think (its been awhile)... take the higher of the two off and stick your finger in and feel if there's fluid right below the level of the hood...if not, fill er up...its a big pain in the ass.. get a funnel w/ a flexible hose :)

to check the fluid in the tranny there is a small dipstick at the bottom of the engine bay, looks like the oil dipstick, read it just like the oil would be read also.