Hi Shravanthika,
A couple of things based on my experience -
1) If you are going for a realtor, make sure he/she is from the buyer's side and not the seller's side. It is important to find out who the realtor is representing and whose interests are paramount to him.
2) Try and get a mortgage prequalification and preapproval. That way you would know how much you can afford when you finally set out to buying a house.
3) Shop for the best interest rates. Usually if you are buying brand new homes, the sellers also try to sell you the mortgage. Don't accept it blindly. Call up banks etc and find out the best rate you can get. If you are a member of a Credit union bank, check the rates with them. They might have the lowest possible.
4) Before signing the contract, get an independent home inspection done - be it an old house or a brand new one. It might cost you a couple of hundred bucks, but it is worth it for your peace of mind.
Hope this helps! All the best with your home buying!
love,
Aarushi