Consider using a Rolodex or a 3x5 card file. If you have lots of time, or volunteers with not much to do, make a database. You can then sort the bookmark list by subject, grade level, class, or whatever makes sense to you. I keep dumping things in and eventually I admit I have too much junk. With bookmarks you may find your curriculum and interests changing.
Sites also change addresses or disappear entirely.
Keep your bookmark file useful and weed it out before it gets too cumbersome. If a page has changed, Navigator puts a special mark on the page's bookmark icon. Unchanged pages retain their standard, unmarked bookmark icon. You can enter a word you remember being in the bookmark's name. The computer will find the bookmark for you.