OK. First of all, here's what you need:
1 (or 2) LP cover(s)...depending on whether you want different images on the front and back
1 length of ribbon (about 10-12 inches...can be cut if too long)
paper CD sleeves with a flap on the top... you can get funky coloured ones here: http://www.yesbuy.net/pacdeny.html
a hole punch
Step 1: Measure one of your sleeves WITH THE FLAP OPEN. Mine were 5 inches by 6, but that might not be a standard measurement.
Step 2: On your LP cover, pencil the outline of this measurement. One of the two shorter ends must fall along a folded edge on the cover:
Step 3: Flip over the LP cover and tack about an inch extra onto this length so that, after it's cut and unfolded, your rectangle will have a spine of an inch after the bend in the cardboard. Usually there is already about an inch of reinforcement inside the cover where one side has been glued to the other:
Step 4: Repeat steps 1 and 2 on a different part of the cover - or a completely different cover, depending on what effect you're going for.
Step 5: Glue the two spine bits one on top of the other with the glue gun so that you've got what looks like a book cover (front cover, back cover and doubly-thick spine).
Step 6: Mark out two Xs on your back cover parallel to each other. This is where you're going to thread your ribbon:
Step 7: Punch a hole on each x.
Step 8: Stack together as many CD sleeves as you're going to include in the case with the flaps open. Line them up inside the case with the edges of the flaps touching the top edge of the back cover, and mark off Xs where they meet the holes in the back cover.
Step 9: Once again, punch out the Xs.
Step 10: Take your length of ribbon and thread it through the back cover like you would a shoelace, with both ends coming through to the inside of the cover. Then thread the ribbon ends through their respective holes on the CD sleeves. Tie the ribbon.
You'll have some excess length on the front cover which you can now cut off based on the size of your CD sleeves.
That's it! Hope this wasn't too confusing. It's actually a dead simple craft, but I'm terrible at instructions.