What is the best way to advertise to a greater market?

I recently posted a blog about two different way to market my company.  I got some great responses that really helped me, but know I've got anothere way to really get myself out there.  I just don't know who or how much it may cost.  I can purchase a commercial for around 1000.00 or a little more, but have no idea who to talk to or how much T.V. spots cost.  Does anyone have previous experience with t.v. advertising?  I would like to learn the ropes of this considering I have 350+ residential lenders, and 1270 commercial lenders around the country that can help a lot of people in need of the perfect loan.  I would really appreciate if anyone was willing to give me a few pointers on this subject.  I believe that my company could really help alot of people and would like the chance to let them knkow I exist.  I plan on doing a postcard drop but am not sure if my money would be better spent on T.V. or maybe even radio spots instead.  Please feel free to let me know any ideas or suggestions you all may have on this subject.  You all have been a great help to me thats why I keep asking for advice. Thanks