Make sure you get the right size seat post.. I know my Nishiki was an odd size (26.6mm) so I couldn't just walk into a LBS and buy one. I ordered mine from Niagara Cycle since they had a few other things I wanted to order too so paying shipping didn't sting as much.

The park tools website has all kinds of little how-to tutorials http://www.parktool.com/

I also have the repair book that Bicycling magazine put out.. it's been handy and I bought it from someone right here on TE