Is it ok if I pick out my own wedding ring or is it supposed to be a surprise?

Lesson 1 -

There are two rings involved in getting married when it comes to the ladies - 1 The Engagement Ring, this is the ring the man buys & proposes with. This is usually a diamond, although more people these days are opting for non-diamond rings and 2 - The Wedding Ring. This is the ring that is exchanged at the actual wedding ceremony. After the wedding, most women wear both rings next to eachother.

There is only one ring (usually) when it comes to the men - The Wedding Ring.

Usually the engagement ring is a surprise, or the lady gives her guy ideas on what she likes. Sometimes (but not usually) the guy brings the girl to the jewelry store to look at rings and she chooses what she likes.

Each person usually chooses their own wedding ring, or they shop together to select them. Some people even opt for a set so their wedding rings match.

its better that you are surprised. and your fiancee should know you well enough to know what you like and dislike so you'll be okay