1. NEVER, under any circumstances, bring any food, candy, pancake mix, whatever, or any beverage which is not simply water into your tent ... do this and the bears will bother someone else who has instead of you.
2. The "ground cloth" goes on the "ground" not inside the tent ... it is intended to keep rocks and sticks from poking holes through your floor ... it should be sized slightly smaller than the floor of your tent as to avoid collecting water.
3. Always set up your tent on a slight slope (usually with your head positioned at the high end) ... this prevents water from collecting under your tent as well as, potentially, urine.
4. ALWAYS keep any food, candy, etc. locked in a bear-proof locker or hung from a tree ... don't keep it in the car unless you've got good insurance ... my buddy was in the BWCA one time and swears that he watched a bear try to use his claw to untie his food-bag rope ... I've had two bears in one day (no, they weren't one bear ... they were different colors and sizes) empty two food coolers (except for fat free chips and rice cakes ... for the wife) ... my buddy and I were a couple miles away shooting our .45's when the first one attacked and ate everything ... I scared the he11 out of the second one that night with my .45
5. Which brings up a good point, keep a pistol handy ... it needn't be big as the sound alone will scare a black bear away ... during the aforementioned attack, neighbors used an airhorn and my wife used the car horn, neither of which even got so much as a look from the bear.
6. Pack a couple 5-6 gallon jugs of clean water ... you never know when the well pump will pump nothing but rust ... seen it happen.
7. Pack, at least, a 16' x 24' el cheapo tarp (shouldn't be much more than $10) and 100' of cheap rope ... if you're camping, it WILL rain ... it's only a matter of "for how long?" ... it might be nice to have a few dry square feet ... you're not going to sit in the tent all day.
8. Pack some newspaper and kindling ... maybe even a couple cords of firewood ... in case all the wood around the site is wet ... and don't forget a little "boy scout juice".
9. While not nearly as important while car-camping, it's a good idea to pack good quality rain-gear ... if it ain't breathable, you're likely to end up wet anyhow.
10. Also while not nearly as important while car-camping, a comfortable pair of waterproof boots are nice too.
11. A small portable propane grill (uses the little disposable propane bottles) is great for cooking ... even if it's not raining ... they're only about $20-$30.
12. EARPLUGS! ... if you're not sleeping in the tent alone.
13. Extra batteries.
14. Oh ya, if you've got an extra $30, get one of those Tikka LED headlamps ... they're awesome for grilling in the dark.
15. A canteen or bota is pretty slick if you're going to hit the trails.
16. A $5 pair of welder's gloves is nice if you're going to handle a tripod.
Well, that's all I can think of for now. Oh, and don't forget the beer and beans;f