the good thing about interval training is that you can do it every day, cos your not giving your muscle such a pounding as when you run for 45min+.
So if your really really wanting to get in to shape you will do 20mins of fast interval training every day. No rest days cos you wont need it and the fitness and weight loss is mor important than you muscle growth to start with.
remember that when you have more muscle mass, your metabolism will be much faster, so its easyer to stay thin, when you put on mass. how ever you will put on some weight when you build muscle cos you need to eat lots.
I presume you missed out your legs cos you'll be exercising a lot. dont forget to add leg workouts when you get to your target weight.
I think this work out plan.
20mins CV everyday, change from skipping, running, running up the stairs, boxing, burpies (press up, then stand up, jump up in the air, then press up etc) or even jumping round the garden any thing that will exhaust you quickly. Then for your weights.
monday - 5min warm up - chest, biceps
tues - 5min warm up - core (abs, obliques, lower back)
wed - 5min warm up - traps, shoulders, triceps (i.e. shrugs, rows, shoulder press)
thurs
fri - lats, core, biceps and triceps
sat
sun
this way your gonna be getting fit very quickly, but if you get tired or you have weekend plans, it wont effect your workout if you miss out sat and sunday. you were working your cest and shoulders together which is ok, but shoulders are best worked with traps, this way you can do close grip upright rows witch is a killer for your shoulders.
for a good core work out read
http://www.fitness.com/forum/showthread.php?t=8139 tuesdays core workout can be done on monday or wed, but I'd rather giv it its own day, cos its a huge muscle group.