Make a side area with all the graphics tiles for the map so that you can just select them out of there, and using the mouse will put the tile down, check box's for the nonwalkable tiles etc...i have an example of a map editor written in visual basic that might help...
link: http://home.kc.rr.com/megalodonsoft/Files/MapSource.zip if thats the latest version it will have the features i have mentioned

The reason i am saying this is because i wouldn't mind becoming a map editor as well
