There are a few things that I want to hit on here...
First, as Stefano says, you're not going to turn into the Hulk overnight. Make sure that in addition to any resistance exercises that you're also doing plenty of stretching between exercises and at the end of your workout. Experiment and see what works best for your body. Traditional advice is 12-15 reps per set for tone and 6-8 for size and strength. The actual exercise will change that a bit of course. I've also seen some evidence that goes contrary to the common wisdom, but I would still suggest higher reps and lower weight if you're looking for tone.
You mentioned cardio for losing weight, but I'll tell you what I tell everyone who's trying to lose weight - one of the best things that you can do to lose weight (besides improving your diet) is resistance training. Cardio is great, but only causes an increase in metabolism during the exercise and for a short period afterward. The added muscle from resistance training burns extra calories 24 hours a day. Definitely still keep up with the cardio though, especially if it's something that you enjoy - if exercise is a chore you're much less likely to stick with it.
Finally, if you're just starting out with resistance training then I'd stick to full body workouts for at least the first couple of months. Split routines are best for experienced lifters who are able to push their bodies to the fullest. They can use the targeted workouts to do more exercises/sets/reps for each body part and the extended period of time between workout of any given body part lets them fully recuperate.
If your body isn't used to resistance training then it's going to be counterproductive to spend a lot of time on any one given body part. You're likely to over train that body part which can actually cause muscle loss since it can't heal fully and grow in between workouts.
Start with just a couple of exercises for each body part to begin with and workout every other day (M-W-F with an extended rest on the weekend can work well, but do whatever fits your schedule). After a couple of months, once your muscles have gotten used to the strain then you can switch it up and start splitting your workouts by body parts.
The push/pull that md5sum mentions is one great way to split workouts. One reason that it works is that a lot of the muscles can be "pre-exhausted". Start with the larger muscle groups (say, chest) then when you do the smaller muscle groups (for example, triceps) they're already a little tired from the earlier exercises and you can use lighter weights and fewer exercises while still pushing them to exhaustion. By the time I'm done with flat bench press, incline bench press, and shoulder press it doesn't take much to finish off my triceps.