There are 3 programs you can use to make or edit islands:
1./
WrpEdit........The first one to appear. some people find it hard to use and it is time consuming on some tasks, but, it is more powerful than a lot of people realise.
Available here:
http://www.ofpec.com/editors/browse.php?browsewhat=3&category=3_72./
Visitor..........The official tool from BIS ....second tool to become available. You will need the viewer Buldozer also.
Both are available here:
http://www.flashpoint1985.com/breathe/index.html3./
WrpTool.......The last tool that became available, it does require that you are using Windows XP. A bit of a limitation as a large portion of people don't, including me. And I don't want XP either.
Available here:
http://flashpoint.nekromantix.com/wrp.phpWrpTool comes, if I recall correctly with a very good comprehensive manual, which explains a lot more than just how to use the tool.
There is a tutorial for Visitor available from the download site, although I haven't read it, so can't comment on how good it is.
Try the OFPEC Editors Depot....Tutorials Section, for manuals and tutorials for WrpEdit.:
http://www.ofpec.com/editors/index.php.
My advice, get some tutorials and manuals and read them, then you will maybe know what tool suits you best and what other resources you might need to get started.
Planck