hi, and welcome to the boards...
first let me start by saying that, unfortunately, i think your bf reading is wrong (assuming you're female)... (as a comparison, i'm 5'3'', 117lbs and 16%)... unless you are VERY muscular (which, from your questions, i'm assuming you are not)...i would get another bf reading done so you have an accurate measure to track from as your weight (fat) loss and muscle shaping begins... (you may need to be prepared for a number the higher end of the 20's... or even the low 30s, but please don't let that discourage you though...)
the best thing to do when starting out is to get a trainer (or knowledgeable friend) to work with you... a trainer is a great investment for someone new to the gym since they can show you the ropes and help you get a basic program together...
a good program for a beginner would work all major (legs, chest, back and shoulders) and minor (biceps and tricpes, abs, calves) at least once a week (but not more than twice..)... you could split your inital routine into upper body and lower body days and hit each group twice a week... once you get the hang of this type of routine, you'll probably want to give a little more concentration to each muscle group by developing more of a split routine (a day for each major muscle group), and then hit the muscle only once a week...
when training a major and muscle group together(i.e. Chest and Tris) you should work the bigger muscle first (with bench presses, flies ect), since if you worked the other way around, your smaller, minor muscle (triceps) would fail before the major one (your chest), not allowing your chest to get a proper workout... (so hit chest first then tris, which will already have been worked fairly well from the chest exercises, so they shouldn't take long to fatigue)
as for supplements, the best supplement is food, you have to eat enough, clean food to support your activity... (if you'd like to post your diet, we're usually able to offer areas of improvement, or at least let you know you're on the right track)... you should be eating 5-7(small) meals a day, spread 2-3 hours apart on average, so your body is getting a constant supply of energy rather than a lot of food a couple times a day...
other supplements that are useful include a good protein powder and an eca stack (fat burner for before cardio)... as your training progresses, you may want to add creatine and glutamine (for muscle building, repair and recovery)... you probably don't need those at this point in time, but in the near future, adding them into your regiment might be a good idea... a good flax seed oil (EFA) is also a definate if you don't already have one...
now, back to the gym... start slow and light and get the form down, (watch people, get a trainer if you can, read around,(a good body building book/magazines are always helpful since they have pictures)...) and make sure that you're doing the motion correctly before you add weight.. once you get the motion down safely, add weight that challanges your muscles.. lift as heavy as you safely can, fatigue those muscles... don't be afraid to sweat!
good luck and keep us updated...