This simplified series of articles from Fire Mountain Gems shows how easy it is to get started bead weaving. http://www.firemountaingems.com/resources/jewelry-making-articles/ec97?cid=675379206424534043&_rid=295108.1704.125139&WT.mc_id=NL150331
A very simple loom can be made at home.
You will need a small wooden picture frame (just the open frame, with no glass), two screen door springs (the fine bouncy ones) or other springs that are at least the width of your finished work and have ends that lie perpendicular to the length of the spring and can be screwed down, wood screws and washers.
Lay a spring on the edge of the frame and mark the position where the screws should be. The two springs should be on opposite sides.
Drill pilot holes for the screws. Lay the spring end over the hole. Place a washer on the screw, and screw the spring to the frame. Repeat for the other three holes.
If you wish, you can screw in a cup hook on each end to hold the threads and to keep the proper tension.