It's normal for a guinea pig to be afraid of you at first, and
     some guinea pigs, depending on personality, are always a little
     shy.  However, with patience and love, you can almost always make
     good friends with a guinea pig.  The younger they are when you
     start, the easier it will be to gain their trust.

     The thing to remember is that you are very large and frightening
     to a guinea pig.  Also, being picked up is _very_ scary, since
     guinea pigs aren't really climbing or jumping sorts of animals
     the way, for instance, hamsters are---they're used to having four
     feet solidly on the ground.  It's much easier if you start when
     they're little, so that your hand can support more of the body at
     once.  The best way to pick one up is to place one hand under the
     belly and lift, then as soon as they are off the ground, place
     another hand under the hind legs so he (or she) feels secure and
     supported.

     Put him in your lap---maybe on a towel so you don't have to worry
     about "accidents"---and pet him to your heart's content.  Some
     guinea pigs also like being held standing against the chest, with
     the nose pointing up towards your face, or cradled in your arms
     at chest level.  Try different positions, and you should be able
     to tell which one(s) your guinea pig likes by how restless they
     are.  This is a good time to give fresh vegetable treats, so he
     feels positively about the experience!  As soon as he begins to
     squeak or become restless, let him down.  Besides the fact that
     he'll become enthusiastic faster if he isn't imprisoned on your
     lap, it also may be a sign that he's about to pee.

     Some guinea pigs never feel comfortable being picked up,
     especially if they aren't handled a lot when they're little.
     This doesn't mean that you can't have a good relationship with
     your pet, though, just that you have to relate to him (or her)
     where he's more comfortable, namely on the ground.  The best time
     to do this is during play time, when he's let out to run around
     the room (this should happen every day, so they get enough
     exercise).  Lie down on the floor, so you aren't so tall and
     frightening, and offer a piece of vegetable to your guinea pig.
     While he's eating it, reach forward slowly to pet him.  If he
     runs away, let him finish his vegetable and try again later.  It
     may take patience, but eventually the shyest of guinea pigs
     should sit still for you to pet him, and even come over to be
     petted.  The more time you spend on the floor with him, the
     faster he'll get used to you.  Also, the less you chase him
     around to pick him up the less afraid of you he'll be, so if your
     guinea pig lives in a cage, try to set up some sort of ramp so
     that they can get back into their cage on their own.  If you put
     fresh vegetables in there, or just rattle around their pellets a
     little, I guarantee they'll go back into their cage without more
     forceful urging.

     Remember, the more time you spend with your guinea pigs, the
     faster they'll become friendly with you!