When buying beads to make your own jewelry, don't forget all of the other materials which you will need. In addition to beads and finished jewelry, my Ebay store offers a variety of the supplies listed below. 

Some common jewelry-making tools and findings include the following:

elastic cord (great for bracelets)

memory wire

tiger-tail cord

end caps

pliers

wire nippers

crimp beads / crimp covers

jumprings (soldered or open)

headpins

bails

toggles, lobster claws, etc...

bead spacers

bead board (to plan your design)

pearl reamer

magnifying glass

Also, whenever making your own jewelry make sure you have a camera at your disposal - take pictures of your designs!