Know-How Exchange : Advertising/PR

If you are starting from Zero:
1. List all your goals
2. Create quarterly or semi-annual targets
3. Create plans for attacking those targets
4. Research costs to accomplish all the plans
5. Lay costs out on a timeline (monthly) so you can adjust as the calendar progresses
6. Add up totals by plan, by month
7 Add up all the months

You now have a budget.

Hope that helps.

The key will be defining your goals and the value of achieving them. For example, if you need to generate 60% awareness among your target audience, then you'll have to find a way to reach those people with your message. If the cost to do so is greater than the value, then you probably don't have a viable proposition.

Also, you might need to consider the frequency with which you reach your target audience. How many times do they need to hear your message for it to sink in? When you determine that, then you can add that to the mix of things you are considering.

Etc. Etc.

It all begins with defining your goals very carefully.