How often should you work out?

I have heard a lot of different opinions on this, and just needed a little clarification.

I just recently bought a gym membership and have been going every single day. Here's what my routine consists of:

Warm-up: 3 miles at moderate pace on the stationary bikes. This usually takes me about 15 minutes to bike 3 miles.
Various machines. It really depends on the day, but on the different machines, I do 10 reps, 3 times with each machine. My favorites are the inner thigh machine, tricep machine, and ab lounge machine.
10 minutes on the elliptical trainer.
10 minutes on the stair master at level 3.

By the end, I have had a great work out. This usually takes me about an hour.

My question is...how often should I do this? Is my normal habit of going every day good, or like I have heard before, should I stick with 3 to 4 days?? The days that I don't go to the gym, I feel so horrible and guilty for some reason.

I think 5 days a week is plenty, then on your off days you can do something you enjoy outside... such as taking a walk, rollerblading, etc.  This way you won't feel guily about not doing something active or exercise
Also make sure you are varrying your routine every couple of weeks so you don't get burnt out!  I hope this helps!

Try not to do cardio on the same day as your weights, you can't do either effectively if you're trying to do both. Ideally if you're doing five days, three of those should be weights ONLY.

Scrap that weight routine and favor the big five compound exercises: squats, deadlifts, bench press, shoulder press and barbell rows. There are numerous sources online to show you the correct form. Unless you're a bodybuilder trying to finely tune your body, the resistence exercises you're doing are just not effective. Do three sets of 8 of those five exercises (increasing the weight each set) and you'll notice a marked improvement.

Good luck!

don't worry about the dead lifts that maybe too advanced for you, do your cardio after the weights for a better fat burning effect, and only do weights 3 times a week, and get at least 2 days off per week