Many of the posters here have no clue about even the simplest debugging, or about how to use the debugger to step through code. I often point them to this post
http://www.access-programmers.co.uk/forums/showthread.php?p=705111#post705111

which covers mutiple issues , and also contains some essential pointers as to how to debug (but that is not reflected in the title).

I think perhaps the post, or a slightly modifed version could play a useful role as a sticky.