I see somebody else came from the backpacking world. OK.
Some trailer stuff is usually need like chocks, leveler, jack, road flares, etc.
Besides that stuff here's my list.
One maybe two change of clothes. Clothes selection for layering. (the extra change is addition from the backpacking)
Two sleeping bags, sans sleeping pads. (worked good in the tent so will work good in trailer)
Two sleeping bag liners. (Mostly for warm nights when the regular bags are too warm.)
4 pillows. - real luxery items compared to inflatable pillows.
1 1.1 lieter tea pot. (moved up from a .8 lieter)
2 nesting pots, sans handles. Pot lifter works great.
2 Sierria cups. Work for coffee, soup, and dinner plates.
table ware set for 4.
1 Butane lighter to light
the stove with. (Matches when backpacking)
2 mini-mag flashlights, the AAA type.
1 Very little folding table.
A hot pad, a dish towel, and a hand towel.
Dr Bronners Soap, small bottle.
One thermos coffee press. (1 lieter, works great and tea pot's just the right size)
Also have a couple soup cups, but I might take them out. I doubt if we'll ever use them.
A digital camera.
No DVD, VCR, TV, Sterio, etc. (PDA, and sometimes an old, old laptop computer, it won't play DVDs.)
One pair of binoculars.
Not a lot of stuff.
One small plastic tub with about a weeks worth of food. We usually add a bit that needs to go in the fridge
. A few bottle of soft drinks also go in the fridge
The tug gets a couple folding chairs and depending on what the plan is backpacks, hiking boots, day packs, and a couple bags of woodcarving tools.
That's pretty much it.