Go and see some tents in real life setup in a shop etc... I got into camping a few years back and loved it, just not been able too go for a while, roomy tents are good. I prefer comfort, so I have a short tent with 3 sections (2 bedrooms and a centre room) with two air beds and a 12v pumps, so your nice and comfy and don't feel the cold off the floor. However tall tents where you can actually stand up are even better but some people say that's too much luxury and not a real camping feel, I beg to differ after crawling around like I'm in a mine. Another good thing is you can get butane heaters that use the same canisters as the cookers, very good with chilly nights especially with kids, makes a huge difference when in the centre of the tent, even if your in a separate room and they are quite economical to run.
I remember one time I fell asleep in the bed and we had a huge down pour, around the Hythe Kent area where I was staying, woke up feeling like I was on about, the tent was in a foot of water and the air bed was floating, got out the tent going wtf, only to find ducks swimming around it, the field was completely waterlogged! Also if you can speak to someone who's been camping or try to join them to get an idea of what you need, my sister came along with me to Brighton with her son even though I told her she's got the wrong stuff and her tents not suitable. Lets just say her tent was the a two man beach tent, later on that night my nephew and her got so cold they were in my spare bedroom going "you where right".
