Google published a guide to help you creating a new AdWords campaign:
- Identify your primary goal - Why do you want to advertise on Google? What audience are you trying to reach? What sort of action to you want people to take when they see your ad? Do you want them to donate to your organization? Attend your annual event? Or simply be aware of your foundation?
- For each goals create one campaign and use language and location targeting settings to pinpoint your audience. If you've a national organization, but are only looking for volunteers in certain city/state, location targeting can help reach the audience that's most relevant for you. You can also use language targeting in same manner, such as targeting Spanish if you would like to reach Hispanic population in a certain city.
- Consider different messages you want to get across. These separate messages can be expressed in different ad groups.
- Use Keyword Tool in Opportunities Tab to help expand your groups of keywords. You should've a list of around 10-35 keywords per ad group.
- Optimize as needed - Once you fill out each ad group in your campaign with appropriate number of keywords make sure to check back as often as you can to see how everything is performing. Continue to make adjustments to your campaign, such as adding negative keywords and deleting poor performers, to make sure you're getting the most optimal results.
More Info: AdWords Help Center