Bike seats are not as comfortable as other kinds of seats for obvious reasons of their design, so there is a certain level of comfort that simply doesn\'t exsist on them. That said, there are several things you can do to adjust them to get a more comfortable ride:
the seat should be possitioned at a height so that you\'re sitting comfortably with the leg just slightly bent at the knee when the pedal is at it\'s lowest possition. you never want your leg to go completely straight (lock out the knee).
Keep in mind that because your ankle will bend as well, you want to make sure that the seat height accounts for keeping a bend in your knee no matter what possition your ankle is in.
once that is set, as long as the bike is the right size for you, you should be fine. If you\'re really uncomfortable all the time (back, shoulders, neck) bring it to a shop and ask them to measure you for it. you may be on a bike that is too big or too small for you. The seat can be sliden forwards/backwards until you find a comfortable spot for it. You can also sit on a seat in several different ways front and back to adjust comfort level.
If it\'s still uncomfortable, look into getting a bigger seat. some seats have springs built into them for shock absorbsion. others are wider which gives more cushioning. There is a difference between mens and womens seats. You can also get gel seat covers that slip on to give the seat you already have more padding.
You can also get a pair of bike shorts, which have padding in them, as we\'ve discussed earlier in this thread.
I\'ve also seen bmx bike shorts that are normal looking workout shorts but they have the padding in them so that no one would know you were wearing them.