Lost Mine of Phandelver
The Starter Set Companion (Pay what you want)
(Text below Lovingly copied from a post from /u/OneCritWonder)
A video for brand new DMs who will be running the Starter Set. It does have spoilers so the players shouldn't watch it, but there are some decent pointers and important rules explanations in there.
Don't have 5 players? This tool shows you how to re-balance the fights.
These cheat sheets are really handy for some folks.
Maps & Handouts
I made an Actions In Combat handout that I print out for each player.
This album of Maps for the campaign are free use. If you want high quality versions of the ones from the book, Mike Schley sells the entire bundle for $10. Includes high-res versions for both the DM and players.
This thread has lots of user made maps you can look through as well.