Some of you probably know what it is like to want to post that you have finally begun your project. I have been spending alot of my free time for the last 2 years on this forum and the day has finally come!

So here are some of the details so far:
Starting out with the smaller of the Harbor Freight trailers, I replaced the tongue with 3-inch channel to get the length I need on the tongue. The frame of the box is primarily 2x4 construction on top of the steel kit. I have completed the baseboard (floorboard) and at the point where it contacts the trailer frame it has doublewalled contrution and is braced by additional 2x4s.
I have the underside coated with black oil based rust-oleum and I am thinking about using one of the sticky undercoatings I see talked about on here all the time, I'll have to use a friends garage (with a pit) ten the tim comes for that. I am opting to wait cause I want to really sealit all up tight and I expect to be cutting a vent for the AC to vent out the floor.
I cannot believe how rigid the frame is, my wife and I spent time laying on the trailer (yeah no mattress, backache) to check for fit as soon as the floor was in. I have opted to build 2x2 framed walls and have nearly completed the first one. I was given 2 brand new sheets of oak Luan by an interested neighbor who saw what I was working on. (It is amazing the attention this thing already draws and it is not even close to being done. The free Oak settles the enterior treatment question.
The end product will be roughly 4x8 with a 4 foot ceiling (I have a small 1 car garage to store this in.) Part of he sizing isbased on the fat that I am planning on using 3 baby mattresses for the bed (curious if anybody has tried this) so that we can stack the mattress up and out of the way under the cabinet area. I have a new/used vent window from a new cargo trailer my dad bought, he put a fantastic fan/vent in right away and saved it for me. I have been collecting other bits and pieces that will add to the project. Trying to save the dollars for windows, hinges and door latches.
Tab so far:
*Harbor Freight trailer - Free (given to me by my brother, I originally bought and assembled it a couple years ago for 175 or so)
*Lumber 60 bucks (estimated so far)
*Steel for Tongue extenion (free, it was part of an electric gate for a gated community)
*Fun building and painting with my 6-year old and wife - Priceless