I've started a GitHub repository containing some basic JMeter test plans. While creating test plans is fairly straight forward, I find it easier and quicker to take an existing test plan, and tweak it to suit my needs. Maybe it will help you as well. Right now I've got two up there, one using the JMeter Standard Plugins to do a constant load, and one with a simple loop controller loading a web page with 20 users, with a 5 second delay. I'll try to add more useful test plans over time.