What is the sizing like? Do they run large or small?

For the most part the tees run fairly standard.  We have a size chart for each shirt that can be expanded.  Just look for Exact Size Chart for This Product.  Due to variations of manufacturer runs our measurements can vary by up to an inch from the published numbers.  We recommend that you take a shirt that you love the sizing of and compare to our size chart, and then allow for some shrinkage if you are ordering a mostly cotton tee.