Most community colleges will have a real estate department/program. Check with them -- they will be able to steer you and might even have a buyers course. Might also check with your city/county government. They generally handle the "first time buyer money" and will often have seminars to get you started. If you're in a large city, you'll probably have a HUD (Housing and Urban Developement) office. They will certainly have guidance and information for you. If you're a veteran, the VA has great programs to get you started. Some title companies will have programs for first time buyers.
The best place for money is a private lender --family, friend, etc. Credit union and other lending institutions (Wells Fargo, BOA, etc) are next best. I'd suggest an independent mortgage broker only if you have problem credit. I'd avoid the zero down scenario if possible. If you have to sell the property in a few years, you might find yourself "upside down" on value -- the payoff might be more that you would net from a sale. The more down you make, the better the terms (usually). The ideal on a note is to do 20% down. Much easier to qualiy, you generally can avoid escrow for taxes and insurance, and you will not have to purchase PMI (private mortgage insurance) which can add a bunch to your payment.
If you ask around your relatives, friends, etc. you may get the name of a Realtor who has handled a couple of satisfactory transactions for them. A good, ethical Realtor can lead you through the process very well Emphasis on the "good, ethical" part. I would use a Realtor only through a trusted referral. Don't just call a large brokerage and hook up with the first agent you talk to. Trust me -- I'm a Realtor/Broker.