Sharon,
I've been living in Budapest for the past 5 months, and it is fantastic city. The trams, subways, and the buses are very easy to use....ticket booths are available at all the major stations. Look for the sign that says "jegy" which means ticket. When you are on a bus or tram, there is a litle orange box located usually by the door. Put your ticket in and it will be stamped with a code for that ride. However, remember that you need a new ticket for each ride. If you're caught without a valid ticket, it is fine of 5000 huf which is about $25.00. If you choose to use a taxi, use City Taxi, and have your hotel call a cab for you. If you just hop in a cab that's parked on the street, it will cost you twice as much. The only other advice that I can offer is to try and learn a few Hungarian words, and enjoy your trip!