Brand New has a concise listing of The Dirty Dozen, the 12 basic types of advertising. Pretty good resource.
When you read through something like this, it’s easy to think that it’s all common sense, something you already know. So you move on. I challenge you to read it in terms of your company, or a particular product or service that you market, and figure out a) which ones you currently use, and b) how you could possibly use the ones that you aren’t currently using. It’s much easier to brainstorm when you can think in terms of a specific product or company.