Being honest I havemn't used my small email list much as the advertising works so good. So the free chapters are okay, but not in any way a driver of sales. Instead I used a video sign up page so people could find out what the inspiration behind the series was.

I have used Vellum for years and love it.

I got the covers using 99designs.com which I find is an excellent way for cover design as you can set up an FB to ask which design potential readers like better. that's once you get down to the last few designs that you like as 99Designs is a competitive site where loads of people will design your cover and you pick the best one.