So why do people lose hair?
Hair loss can be caused by many things including genetics, stress, diet, medication and most commonly hormones. Typical male pattern baldness can be held at bay and often reversed by daily use of Propecia. The original drug Finasteride is currently used to treat enlarged prostate but was found to increase hair growth so it was re-packaged as a much more expensive hair loss drug. Another weapon against hair loss is a topical solution or foam like Minoxidil or Rogaine
As a general rule the less hair you have the shorter it should be cut, don't do the pony tail, mullet, comb over thing! I always cut thinning hair dry so I can see how it falls naturally, it's a fine line between too short and just long enough for coverage. If you have a good head shape and nice features you may be a good candidate for just shaving it off. If you're thinking about shaving your head, go see a barber and cut it very short with a 1" or 2" guard that way you can see your head shape before going full Kojak.