I have a horrible posture... slouched over a computer all day will do that. I've considered focusing on back exercises more when I get to the gym soon, and I'm curious what exercises I can do at home without a gym for posture issues? Basic core exercises? I can never quite find an exercise that matches with the type where you are facing down, lock your feet in and then raise yourself upward with you back muscles.

Any tips?

Well...if you have a large Swiss ball handy, you can do Elbow Planks.

Start off holding E.P. for 15 sec. or whatever.....work your way up to holding for 2,3 min etc. or longer.

Good all-round core/posture developer.

I have a horrible posture... slouched over a computer all day will do that. I've considered focusing on back exercises more when I get to the gym soon, and I'm curious what exercises I can do at home without a gym for posture issues? Basic core exercises? I can never quite find an exercise that matches with the type where you are facing down, lock your feet in and then raise yourself upward with you back muscles.

Any tips?

You can use a swiss ball to do hyperextensions.

http://www.askmen.com/sports/fitness_top_ten/36_fitness_list.html

In addition, you should make sure you're working your rear delts and not overworking your chest and front delts. Face pulls are a fun exercise that hits your rear shoulders and might help with posture.

Make sure to include some back exercises that focus on scapular retraction. When doing rows, really work on pulling your shoulder blades together. I have heard an analogy of pretending to hold a tennis ball between your shoulder blades.

I too was a habitual slouncher

About a month after starting my routine I noticed I began standing up straight without thought

I attribute the change to the squats in my routine