Hiya Nekron and Welcome

The stickies in the Macro's & Addon's Forum will have a TON of useful information. Here are a couple posts to get started:

http://www.dual-boxing.com/forums2/viewtopic.php?t=1219

http://www.dual-boxing.com/forums2/viewtopic.php?t=1220

I use keyclone for boxing 2 accounts on 1 computer and it's easy as pie to set up. I haven't tried it on a dual-monitored set up, but I don't see it being an issue. Don't have any experience with AHK, but I'm sure someone will provide some input.

After you get keyclone (or whatever keyboard broadcaster you want to use)and set up some macros....go pwn some stuff....lol. It's really just that easy. You don't need to know coding to multi-box. Just copy the macro's you want to use, change the spell name/character name if necessary, then your good to go.

It'd be a good idea to update your Graphics Card. That GPU will probably struggle quite a bit to run 2 instances of WOW on dual monitors. Your processor and Memory should be OK though.

This is a great community so if you have any questions, don't be afraid to ask.