Jus wondering can anyone help me. Any weight lifting excersises to build pectoral muscles? I have a set of free weights but no bench

Though probably better for toning, push-ups are still a great exercise. You can vary your hand width from very close to very wide, elevate your feet to put more weight directly over your arms, or for a real challenge, have someone light sit lightly, positioned sideways, on your upper back (toward your shoulder blades, never on your lower back). Please don't do this if you have any known back problems of any sort.
Using either a barbell or dumbbells. Holding the weights with your palms facing rear (toward the floor while lifting), lift to shoulder height with arms kept straight, then slowly lower. Though not great for specifically isolating the chest, this exercise will considerably develop your deltoids as well.
Lying on a firm bed use a dumbbell to do a butterfly press one side at a time. Keeping one arm extended out all the way over the side, keeping your elbow moderately bent, palm facing up, raise your arm to a vertical position, then slower lower.
This should get you started anyhow. I'll let you know if I think of any others. Hopefully other people have more suggestions. Good luck. :)

Well I had discussed this issue with my friend a few days ago on another forum by the name of http://www.imsickofbeingfat.com/* and he gave me very valuable tips

Lie on an incline bench with the back rest tilted at an angle of 300 to 450.Support your legs either on the ground or on the platform provided for this purpose at the lower end of the bench.

Take hold of the barbell with your hands grasping the bar far enough apart so that the forearm forms a right angle to the upper arm when the upper arm is parallel to the floor.