Permanent mount NMO antennas are the best way to go as far as grounding and performance are concerned. If you are absolutely opposed to drilling a hole in the vehicle, I would at least recommend going with some sort of a trunk or hatch mount antenna. A magnetic mount antenna would personally be my last resort, although that's not to say they don't work at all either. You will probably want to purchase at least a VHF 5/8-wave antenna with 3 Db gain for the best performance on two meters in rural areas.
I would strongly recommend that you hard wire and properly fuse your ham radio, as powering from the cigarette lighter is not recommended for anything over 5 watts PEP. Some of the newer ham rigs have weather bands with weather alert built right into the radio, negating the need for a CB radio for weather reception.
QRZ is a great site for taking practice tests, but I always recommend that you purchase the licensing manual (i.e. Now You're Talking from RadioShack) and actual read the relevant portions. This will make you a more knowledgeable operator and it will explain radio etiquette in greater detail.