jnlabay,

Welcome to the Forums.
There are a few folks here who have done the Houston/Austin MS150. Do a search
on MS150 and you should get some hits. If the members are still active you might
send a PM or e-mail.
I haven't done this particular ride but I know that the MS150 up here in Dallas
has training rides every weekend, they would be a good start.
Drink Alot of liquids, and eat before you feel hungry. I think one of the biggest
problems is that folks don't fuel enough for these rides.
The other thing that is paramount to a great MS150 ride. . . .
have fun.

Marty