Here are some answers to your question:
1) As a first time home buyer you are eligible to take advantage of the $8K Tax Credit
2) The first thing you want to do when starting your real estate search is get Pre-approved for a loan, then select an agent to help you in your search. If you do not know a financial professional that can help, select a real estate agent and they can suggest some names for you
3) The type of property you purchase depends on your needs and wants. That is something you'll need to discuss with your financial professional and your agent.
4) Mortgage options can be discussed with your financial professional depending on what type of property you want to purchase and for what purpose.
5) The tax credit can only be applied to a home that will be your primary residence for at least 3 years. If you plan on purchasing a multi-family in which you will occupy one of the units, you should be eligible for the tax credit. If you live in the unit for the three years and move out after that time, you will not need to re-pay the credit. However, if you do not plan to live in the property and use it only as an investment vehicle, you are not eligible for the tax credit.
6) To find a professional real estate agent to work with, ask your friends, family, co-workers etc. who they have used in the past and liked. Otherwise, do your research here online and interview a few people to see who you feel the most comfortable with.
I hope that helps with your question! Good luck in your search. You do have time to get in on the tax credit. You only have to have a signed contract by April 30, 2010, and you'll need to close by June 30, 2010.