i didnt' take a ton of time to read everyone elses post so if i step on someones toes i'm sorry.
your best bet is to get someone at the gym to help you out. you WILL need someone there with your regardless to spot you, never lift without a spoter! The idea is to work major muscles first, and then split your workouts into lowerbody and uper body. my workouts consist of:
one day- bench, lat pulls,deltoids(sholders),traps (up by your neck) triceps, and then biceps. in that order
next day- squats, lunges, power militarys or hang cleans(look them up on the internet, time consuming to explain), both thigh muscles, and calfs. again in that order.
the reason for doing them in a set order is you want to work large muscles first. they recruit fibers from smaller muscles...kind of tough to explain and make sence of it, but trust me it works out.
I take a rest inbetween my two days although you don't need to, and it would be better if i didn't, but i dont' like lifting much. you never want to lift with the same muscles two days in a row, you won't get any benefit other than more muscle endurence from doing that. you need at least a day off for each muscle.
thats a good way to start lifting, although you really should get some help from someone else at the gym, they will have a better idea of what will work for you.
and you also said you want to get in better shape, lifting alone wont' do that. you need to add some aerobic exercise. you can run, bike, or i'd strongly sugest swimming, problem is you need someone to help you out so you don't hurt yourself swimming (it happens all the time). biking is probably the best bet, running is tough on your knees... all you need is a bike, some time, and some water lots and lots of water
I also do about 10 minutes of ab work without rest, all different types of situps. you could start out just doing 100 situps a day, take a little rest if you need to (keep it under 30 sec.) and just build up from there. push ups and pullups will only help too.
and my last and biggest bit of advise, stretch! you should spend at least 10 minutes stretching before you workout, and stretch a little after you workout too especially when you start, it will help keep you from being as sore.
good luck!