As others have said, this is a very frequent, but VERY IMPORTANT topic! Thank you for knowing what you do not know, and coming here for help!
Suggestion #1 Spend several hours reading through threads on this board, Towing & towels board and General board. You will get a very broad base education on many topics you never knew existed or were issues. I have spent a year and a half lurking here, and I still learn something new almost every day.
#2. Look through the Library. Click the tab near the top of the page. More great information.
#3. Look for Travel Trailers (TT) or Fifth Wheels (FW) at many sites. Toy Haulers (TH) would be well worth a look as well.
By far the most important consideration is Floor Plan! If you plan to live in it with 4 kids, it is even more important!! Also, note the difference between "Towable" or "RV" vs "Park Model". The park model, as mentioned, is not intended to be moved, although it can be. (Think mobile home)
#4. In the size you are looking for, the TT market does not have as much as you might expect. That is where the FW market really comes into its own.
While it is much easier to shop new, I suggest you buy used. MANY nearly new, gently used campers are available, but you may need to travel a few hundred miles to get your "perfect" camper.
Used campers cost less. If you choose to sell or upgrade in a year or two, the financial hit is much less. Most new campers come with lots of things that need fixed, which means dragging it back to the dealer for a few days - OR WEEKS (seriously!) Where do you live in that time?? A used camper should have all of those things fixed.
Once you have determined what you want, go on line to find that gently used camper with your name on it.
#5. Note this camper living is generally more expensive than living in a house or apartment. Maintenance on a house that goes bouncing down the road is much higher than on a house that holds still. Winter heating in any climate with overnight temps routinely below 40 deg.F is inefficient and expensive. Daytime temps routinely below freezing are downright brutal!! Campground fees are not free either. How about school for the kids?
As for towing, add together the weight of all members of the family, including pets. Add other "stuff" in the truck to keep the kids happy, food, drinks, games, pillows,..... Add the weight of any cargo and tools to be carried in the truck bed. Add the weight of any truck accessories, like a cap or tonneau cover.
For a TT, find the GVWR for the camper. To the number above, add 10% of GVWR as hitch wt, plus 80# for a WD hitch. Your truck MUST have the payload to carry this. More on Payload below.
For a FW, find the GVWR for the camper. To the number above, add 20% of GVWR as pin wt, plus 200# for a FW hitch. Your truck MUST have the payload to carry this.
Truck payload is the most weight the truck was designed to carry. You just determined how much you will need to carry. By definition, Payload = Cargo Carrying Capacity (CCC) = Truck GVWR - actual weight of the truck. Published and advertised Payloads are based on a bare bones, no options truck carrying ONLY a driver and passenger weighing 150# each, plus a full tank of fuel. The REAL CCC for every truck built since 2009 has a yellow label on the driver door latch post that states the CCC for THAT truck as it left the factory. For example, my F350 in my signature has a published payload of 3990#. The yellow label CCC is 3453#, which I have verified by actual weights.
Payload is affected by body style, crew cabs are heavier than regular cabs; bed length; engine and transmission; 2WD or 4WD; SRW or dually; trim level and options; tire / wheel size and load capacity, etc.
Before you buy any truck, open the driver door and verify THIS truck has the CCC to handle your load!
Most important, DO NOT BUY ANY CAMPER OR TRUCK UNTIL YOU KNOW MORE ABOUT THE UNIT THAN THE SALESMAN. Thankfully, this is not hard!
http://www.rvforum.net/SMF_forum/index.php/topic,90933.0.html
There is no way an F-150 will handle anything much over 10,000 pounds. As JFN mentioned, browse this area of the forum (Towing and Towables) as well as the Trailers & Fifth Wheels section... you'll see lots of threads that discuss "What can my truck pull?" type of conversations.
