Lots of good pointers/recommendations above.
Something for your fur friends: May want to consider having a special carrier with all their stuff in it, ie, food/bowls/toys/blankies/etc and let them sniff at it, both in your house as well as in the trailer. Also consider extra toys/blankies for in the truck, or move one from the carry crate to the truck, so their scent is something they will recognise. Seems to ease the transition to a new/strange place for them.
Did this with my Weimies and they transitioned quite nicely to travelling and being in the trailer.