So many people in this form have ask for the tools they need to mod, so I decide to make a list of all the tools out there (that I know of feel free to add more) and tutorial sites.
Tools
3D Studio Max, for modling ships cars tanks are other objects (no link to demo could not find it) PS this cost alot of money.
Adobe Photo Shop, Good for sking (only 30 day trial)
Editor 42, For map making
MadBull's Map Editor, good for making hight maps like the one above and for placing builds and other things
Unofficial SDK 2, good pack of utillies for doing every thing, most are plugins but other are for makeing and extracting rfa. (there are updated 3ds max scripts at his website)
Tutorilas
The only on I can think of is
this one. It has tutorials on about every thing you need to know
P.S. The best tutorials are other mods and just going through all the files in a mod and finding out how things work.
Good Luck and feel free to add and tools or tutorails.