For now you should definitely start with these:
http://www.pokecommunity.com/showthread.php?t=195659
http://www.pokecommunity.com/showthread.php?t=161616
http://www.pokecommunity.com/showthread.php?t=208837
PKSV is the best beginning tool for scripting imo. It has a user-friendly script generator, which can make custom scripts for you in an instant, requiring little to no knowledge of scripting at all!
AdvanceMap is the tool you need the most. It's like the staple of ROM Hacking. It's not only needed for mapping, but for tiling, scripting, and sometimes even spriting as well.
I'm a bit busy, but I promise I'll get back to you as soon as I can. Good luck!