End Mills and Sharpening

[Robin]

I'v purchase a new Grizzly mill and have also purchased some inexpensive end mills. I was sure I would destroy them as I learned how to use them. I'm wanting to learn about what material the end mill should be made of to last longer.... cobalt, solid carbid or possibly the coated end mills. Also, which ones can be readily sharpened and what is the procedure for sharpening end mills.