Stainless knives are generally harder (also brittle) so it's harder to sharpen. High carbon knives are softer and easier to sharpen.

Without using a belt sander, my favorite method is sandpaper and leather strop. The strop adds that nice finish, but I don't even think it's truly necessary. Really, all you need is some sandpaper and a mousepad, and you'll have the most versatile and cheap methods of sharpening. The magic marker trick helps a lot when you're first starting, you basically color in your edge and after every pass, just inspect and see if you're hitting the right spot.