SC2Mapster

Unit Tester by XGDragon

I'm pretty sure there are many theorycrafter out there who wants to know what are the best units. How do 20 zerglings do facing 12 zealots and that kind of thing. XGDragon made a Unit Tester map that let you choose the units you want and make them fight. It is using a custom UI to help you in that task which is pretty well done. If you want to get the basics of UI, I suggest you to read the dialog tutorial by Voxglhf.

Galaxy for Beginners by mikelat

If you want to start using the Galaxy Editor, mikelat has done 6 videos tutorial explaining how to get started. This is really instructive and he speaks really well (he did more than 1000 youtube videos playing and commenting many games in the "Let's play" serie). I hope you will like it.

Other tutorials: [2.1] Little bit of controls, [2.2] Terrain 101, [3] Starting the map, [4] Fixing & Doodads, [5] Alvin and the Data Editor and [6] Adding abilities

AC130 Escort by Pinworm45

You probably remember the AC130K map I featured few days ago, at the same time Pinworm45 was working on a map of the same type: AC130 Escort. It's an aerial shooter and this one is playable! Enjoy :)