Hi,
For starters, maybe you can tell us what version of MXP you are using, that might be helpful in finding what you need. Are you interested in info about a specific module maybe? Also, where are you? Meaning, what country are you in?
I am not sure if I have any docos for MXP; it's been a couple of years since I last used and worked on the software. But, I could possibly have some CDs left laying around somewhere, so I may be able to dig something up. And, you can always try asking questions on here, you never know how many (former) MXP users are out there
Ohh yes, and there is always Foresight Software:
http://www.foresight-esp.com, you may be able to contact someone there.