Hey Elrathion, I notice that nobody has responded to your thread yet so I figured i'd see if I can help.
Business proposals can be a very daunting task, but after you have done a few it gets much easier. The most important thing is to consider the standpoint of your client. Is this going to be a solicited proposal (they have already contacted you an expressed interest in your product) or an unsolicited one? If the proposal is solicited, you should focus more on how you are going to solve the clients problem. If it is unsolicited, put extra effort into explaining the problem itself.
For example, lets say you are approaching a business unsolicited because they have not done any SEO or marketing on their website. In this situation you would want to clearly explain the benefits of IM, and show them all of the potential clients that they are missing out on by not promoting their website. You want the reader to go read your proposal and be CONCERNED about this problem that they may haven't even realized they had. If this was a solicited proposal, I would to into specific detail about the clients needs. For example, show them ways that their website is being poorly marketed. You could also show them ways that their competitors are outshining them, and make them feel like they are being left behind.
The next part of the proposal is the solution. You have already got your client worked up and anxious about this problem you have presented, and you have demonstrated that you have a good understanding of their businesses needs. This section is where you can really shine. You want to demonstrate how you are going to solve this problem for them. Go into detail about why you are the best person for the job, and the resources you have available to help you achieve your goals.
The last section in the proposal is Pricing. Pretty straightforward, just show them the cost and, if you like, try to offset it by also explaining the potential gains to their business.
In a few weeks i'm going to be opening a new writing service in the marketplace. If you like, i'd be willing to do one of your proposals free of charge. All I ask in exchange is for you to leave me a fair review in my marketplace thread once I launch. I'm pretty confident that after I work with you on the first proposal, you should be able to use my template to complete your other two.