This is probably a stupid question, but how do you make tile sets?

Step 1: If you don't have PSP, get Stencil.pcx out of the JCS help file, and open it in whatever inferior image program you have. (Ok, I'm slightly biased here) If you do have it, open up PSP, and create a new image that is (and this is important) 320 pixels wide, and a multiple of 32 high. (E.G. 960, 3200..)
Step 1.5 (only if you're using PSP): Find the grid settings, and set the grid to be 32x32 PIXELS, then turn it on.
Step 2: Draw the tileset using whatever tools you like. Make sure each tile is only 32x32, and fits inside a grid square. As a general rule, 0,0,0 is transparent. Save it as (usually) either .bmp or .pcx.
Step 2.5 (Only if you need more room): If you have PSP, simply enlarge the image to a higher multiple of 32 pixels high. (Don't use Resize, this will mess up your tiles) If you're using Stencil.pcx, copy a few liens of grid squares, make the image larger, then paste the grid squares until the image is filled up again.
Step 3: Download Palsuit 3 by Toxic Bunny, and use it to change the palette of your image to a JJ2 compatible palette. Make sure your image uses this JJ2 compatible palette. If this is too complicated, forget about this for now.
Step 4: Save the image as a seperate file such as (imagename)M.(extension). Now change everything you don't want to be solid to 0,0,0, and everything you do to some other color. If your tileset is just a bunch of blocks and everything that should be solid already is, don't bother with this step. (But make a different tileset)
Step 5: If they're not already, move both images into the subdirectory Tiles in your JJ2 folder.
Step 6: Open JCS. Click the pink Set button, and when it brings something up, click Add. "Description" is the name of your tileset. "Filename" is (duh) the filename of your tileset. It will automatically add a .j2t extension. For "Tileset" select your main image, and unless you skipped Step 4, set "Mask" to the solid/non solid image.
Step 7: If you skipped Step 3, check the "Remap Tileset Palette" button. Otherwise, don't. Click the "Ok" button.
Step 8: On the list of tilesets it shows you, select yours (it should be at the top), and click the "Build" button. Hopefully, there should be no errors. Click "Ok" twice, and open up your new tileset in JCS.