I'm just about starting an advertising agency and I need to know how to write a proposal for my clients

Here are some resources you may find useful:

Capture Planning: How to Write a Business Proposal
How to Write an Absolutely Irresistible Business Proposal
The Winning Elements of Business Proposals

Also, if you haven't already done so, connecting with the LinkedIn.com community is a great way to network.

Yes, there are many places on the Internet where you could be promoting your business without have to pay a cent. LinkedIn.com is an excellent online community that also gets excellent results when people do searches for things on the Internet. I am a member of it.

If you would like to start your proposal here, then I am sure that there are some of here who could help you with it so that it could be worded the best for your benefit.

Some of the best sites for advertising on the Internet are listed below.

craigslist: san francisco bay area classifieds for jobs, apartments, personals, for sale, services, community, and events

(To use Craigslist, you just find and post on the one that is near you.)

USA - cliQs.com

Everything from Everywhere

DomesticSale - The Effective Free Classifieds

Free Classifieds Ads - Internet Advertising to Sell Online

Vast.com - Search All The Classifieds On The Web

PennySaverUSA Classifieds Online: Local ads in California

Free Classifieds - FinditClassifieds.com

Oodle.com Classifieds - Search local online classifieds

BuySellCommunity Classifieds - Buy & Sell Locally : Free Online Classifieds

Free Classifieds @ Adpost.com

Free Classifieds, Free Ads, Free advertisement, Business Opportunity

Free Classifieds - FinditClassifieds.com

Free Advertising, Free Classifieds, Free Classified Ads, Free Ads, Classified Ads, Free Classified, Bulk Email Advertising, Opt In Email Marketing Services, Email Lists, Classified, Free Ad, Advertising Free, Classifieds, Classified Ad, Free Classifi

http://quadcities.kijiji.com/ You can change the country and city when you list there.

http://www.evelez.net/ Although it might appear to be connected with the one above, it is different. You can also change country and city.

http://www.livetray.com/

http://www.vvnvv.com/index.asp

http://www.alibaba.com/

http://www.alibaba.com/

http://www.hotfrog.com.au/

http://www.kellysearch.com/

http://www.kbclassifieds.com/

http://www.oodle.com/

http://www.olx.com/

http://www.topix.com/

http://www.isell.com/

http://www.kutvclassifieds.com/Main.do

http://www.gumtree.com/

http://www.flugpo.com/

There are also many places where you can have a free website or blog where you could advertise your business, website or anything else for that matter. Some of them can be found by clicking on the following searches.

Free Website - Google Search

Free Blog - Google Search

You can also look into joining something like Google AdSense if you would like to make some additional revenue.

AdsenseGuide - Join Google Adsense