You?ve gotten some really good tips from Bad Cat and Naturally. Using a scrub before you shave will help you get a better smoother shave (same for us guys shaving our face). It is also important that you use a scrub or body wash with a nonabrasive loofah sponge and go over your legs the days after shaving ? as this will help prevent the hair when growing back in from getting ingrown or causing the irritated bumps your experiencing.
I can also recommend a product from Anthony Logistics for Men (this product is also for women) Ingrown Hair Treatment ? this contains Salicylic Acid as mentioned by Naturally and a number of other good ingredients that help remove the dead skin, fight bacteria and free the ingrown hair(s). Using it can also be used to help prevent ingrown hairs from reoccurring. Hope this helps? Mike.