Hey man, I've started working out as well. Just a few pointers that I have gathered from various sources:
Workout sessions: 1 hour or a little shorter, reason being, your body starts to produce cortosone which destroys muscle (I'd suggest researching this yourself)
Supersets: I like them, however make sure you are still picking on a same muscle/muscle group (Flat bench then pushups, [isolation exercise, compound exercise])
Rest: Very important, get at least 8 hours a night. Seriously!!!
Supplement: I currently am using SizeOn, it is working great! Making sweet gains already (flat bench from 35 dumbbells [5 reps] to 50s [3 reps] in 2 weeks)
Also, make sure you are doing a leg day every week!! It will make you feel powerful! For leg days I do deadlifts (probably the best exercise I can suggest, make sure you have good form, also alternate your hand grips) squats, and sometimes lunges if I'm not dead already lol.
My 2 favorite ab exercises are, leg hooked through on decline bench then twists with 25lb weight. (will kill you so good lol) and this one is the best of all:
http://www.youtube.com/watch?v=o-8jNoh_ojA (you can fast forward most of it)
Ya that's basically my advice for now lol, I want to re-emphasize doing deadlifts though; you will need to buy new pants if you wear skinnies or straight leg because your legs will explode. Also you get a huge testosterone boost.
Also, for most exercises aim for 6 reps (Strength>Endurance but a bit of endurance)
EDIT: Also I will add that getting a gym buddy to go with you, or at least get you started is a huge confidence booster.
Also, make sure you aren't taking too long of breaks between sets (easy to get distracted, I use a stopwatch on my phone)(1:30-2:00 is a good rest time)
Also since I'm already telling you this I might as well go into a little more detail, if I'm doing arms (
http://www.youtube.com/watch?v=6aZQaaKy4Fg best bicep isolation exercise IMO) do that with a weight for 6 reps, then drop 10 lbs and go till you can't anymore, then if you are feeling crazy drop another 10 lbs and keep curling!! (might need 2:30 rest after though) This way we are getting strength gains and some toning.
EDIT2: Also, I don't track calories or anything but I find my body just lets me know I'm hungry more often now. Try to avoid letting your body get super hungry (reddit/computering with grumbly stomach, we've all done hehe) besides that I just try to eat a bit more now with each meal, nothing too difficult.