Hi Robert. If you're looking to get into places that are inaccessible during normal gameplay there are a few things you can try.
Making position modifier codes will usually do the trick. You just need an emulator with a code engine. Start your search, jump, and select less than previous value. Then fall back down and select greater than last value. Keep doing this until you have it narrowed down to a few possible codes. I've drawn a crude graph to illustrate where on the screen you can expect to find your character.
The great thing about axis position modifier codes is that if you get a vertical code you can set the value high, at say 10, and float in the air over anything that would distract you from mapping. I've already made Nosferatu codes for this. Screen orientation moves the screen itself. Player position moves your character. x256 pixels moves you an entire screen.
7E0069?? Horizontal Screen Orientation
7E006A?? Horizontal Screen Orientation x256
7E006B?? Vertical Screen Orientation
7E006C?? Vertical Screen Orientation x256
7E006D?? Horizontal Player Position
7E006E?? Horizontal Player Position x256
7E006F?? Vertical Player Position
7E0070?? Vertical Player Position x256
The hacking utility vSNES can also help you out sometimes. You can load up your savestate and pull map data out of it. It can disable layers and change the default background color to make ripping graphics easier. It can also flatten out a screen by killing the mode7 graphics. Depending on which game you're playing you might be able to take gigantic screenshots with it too.
http://www.zophar.net/utilities/snesutil/vsnes.htmlHope this helps.