If you follow this link it will bring you to the download of the aempro software. Now i know you said you wanted a haltech but if you download this software it has an EFI Basics information page that explains alot. It is in the form of a pdf and is 52pages long which I have found useful many times when tuning or just looking for some information quickly.
http://forum.aempower.com/forum/index.php?topic=17194.0
Also, I went and took the beginner and advanced courses at EFI university which were possibly the best classes ever on tuning. This is the website and they also have a ton of info on their forums. The beginner class is mostly reading and asking questions but very in depth. The advanced class is alot more hands on as there are usually only a max of 8 people so its more 1 on 1 and you actually get to tune a vehicle so you have experience and not just book knowledge trying to figure out how to apply it.
http://www.efi101.com/
Hope this helps
Parker@hybrid-racing.com