I would have /msged ApoxyButt, but I found that there were too many things I felt should be corrected about hir writeup that I should just write it up myself. Sorry if this is a "reply".

Point one: Actually, one should not do a cardiovascular workout before doing weight training. If you got at all a good workout, you will be far too exhausted to use proper form (and we all know you need to worship at the alter of the goddess of form!). It isn't a good idea to start out with cold muscles, but a 5 minute warmup of walking/jogging/running/cycling/using a cardio machine at the gym should be plenty to take care of this. Most WT experts I've spoken to recommend doing weight training on different days than you do your aerobic workout, if possible. If not, it's probably better to do weights first.

Point two: There is no set amount of time you need to run/do other cardio activity before you're "really" burning fat. A lot of beginners are not in good enough shape to run for 45 minutes and they should not start there. One should start by doing as much as is comfortable and work up to a workout that is satisfying in length and intensity. If someone is training to be a sprinter (yes, I know, sprinting is not aerobic,) they don't need to run for 45 minutes to train to be getting a useful workout! Your workout is an individual thing and you have to figure out what works for you.

Point three: ApoxyButt is right when he says don't work out more than every other day, but this only applies to weight training, not to cardiovascular exercise. You can go running every day if you want to (though many people recommend no more than 6 days out of the week to give your body a rest that way, this depends greatly on the intensity of your workouts. If you do an hour of walking everyday I don't think you'd need a day off - again, figure out what works for you.)

Point four (and the most important point): You should not do higher reps with lower weights to "tone" your muslces. If you ask any weight training expert (go on over to misc.fitness.weights and give it a try), they will let you know that low weight, high reps does nothing but waste your time and that anyone who uses the word "tone" doesn't know what they're talking about. ApoxyButt defines it as removing the fat from around and within the muscle. This is totally wrong. SPOT REDUCTION IS A MYTH. You can't remove fat from any particular area by lifting with it, you can only remove it through a caloric deficit (either via diet or cardiovascular exercise). And fat from within the muscle? Um, no. People wanting to "tone" are usually women who fear getting bulky from lifting weights, but don't worry, only very few individuals (and very few of them are women) can get truly bulky, and you will not get bulky by accident.

References are difficult, but really good further reading would be misc.fitness.weights' FAQ, which can be found at http://www.trygve.com/mfw_faq.html. The newsgroup itself is filled with extremely knowledgable people (many of whom are professionals and scientists) and is a great source of accurate, scientifically-backed info.
http://www.exrx.net/WeightTraining/Myths.html also covers the same issues in a quick rundown with some info I haven't covered here as well (thanks to MrFurious for this URL).

Odon Lowe Jr. 2 speaks the truth; if one does weight training and then aerobics, the cardio performance will suffer.. this is why I suggest doing weight training and aerobic activities on separate days, one or the other is bound to suffer. But I think if one is determined to do both on the same day, it's best to do WT first because one is far more likely to injure oneself, especially seriously, by weight training under poor conditions than by doing aerobics with tired muscles, especially low-impact exercises such as swimming. However, if one is interested in improving/perfecting one's technique at an aerobic exercise, doing it after weight training would probably be frustrating at best. In summary, do them on different days for most benefits.