If you are truely a noob then more than likely your first games are going to be of the rec league or non sanctioned middle school variety. You may have to clear it with those in charge but find a highly respected varsity or above official and have then literally work the game with you, as in follow you up and down the court. They can help get you in position and help get you looking at what you need to look at. It is much easier to learn doing it this way than have someone observe you and then talk during breaks or worse afterwards. This is better than even immediate feedback. Situations don't always present themselves in the same way again and the opportunity to learn is lost.

You've gotten some good advice. Here a few more thoughts.
1. Remember it takes some time to become a good official.
2. Learn something from every parther you work with. It will be good or maybe bad... but learn from it.
3. Never become an official because you know you can do better than the guys out there. Not necessarily a true statement as you will see the first time you step on the court.
4. Mistakes help you to "own" the rules next time out.
5. Wear good shoes
6. Keep that uniform neat and clean.
7. Have fun...after all they are called games.
8. Use a Fox 40 whistle... preferably a cmg... and fill it up with air
9. Listen to the veterans. They have paid their dues.