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?
Create one campaign per goal - For each of your goals create one campaign and use the language and location targeting settings to pinpoint your audience. If you have a national organization, but are only looking for volunteers in a certain city/state, location targeting can help reach the audience that is most relevant for you. You can also use language targeting in the same manner, such as targeting Spanish if you would like to reach the Hispanic population in a certain city.
Consider different messages - Consider the different messages you want to get across. These separate messages can be expressed in different ad groups. For example, let’s use the goal of volunteering. You might create three separate ad groups focusing on three different messages: Recruiting Student Volunteers, Recruiting Professional Volunteers, and Recruiting Youth Group Volunteers.
Use AdWords tools - Use the Keyword Tool in the Opportunities Tab of the AdWords interface to help expand your groups of keywords. You should have a list of around 10-35 keywords per ad group. For example, under the ad group Student Volunteers you may want to have keywords such as: student volunteering, student volunteer opportunities, after-school volunteering, etc.
Optimize as needed - Once you fill out each ad group in your campaign with the 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 are getting the most optimal results.
For more tips on creating your campaigns please refer to the AdWords Help Center. Good luck!