Full Size Jeep Network

I am planning a trip out to Big Bend in early April. Any recommendations or advice. We are planning on staying in Terlingua and then traveling out to the park during the day. I have been before, but I was 5 years old and do not remember much. I am taking the Chief and my dad is coming along in his Baby Jeep. Not looking for anything extreme, but just some trails off the beaten path.

Any good web sites out there with park maps and trail guides?