AnnIrishman, I think this is a great start.
Some other things I discovered recently:
Shift +/- resize your brush, but don't damage it like halving/doubling will.
This is really handy for me, as I work this way in Photoshop all the time, resizing my brush as I go.
J Toggle spare frame.
I'm finding this pretty handy, especially if I want to quickly make a tileable texture. It's useful to have a separate doc that shares my palette and other settings, so I can just try stuff out.
I'm starting to love the tilemap feature, but also it drives me crazy. I need to figure out how to implement it into a pipeline, especially as it seems hell bent on moving my tiles around. I've tried to lay them out manually and re-import them, but it always flips out in these cases. I suspect I'll have to learn more about this process to get it working. I'm also curious as to whether I'll be able to get tile layers, and tile animations working correctly in my export process. I might use layers to behave as my colliding and non-colliding areas, but it would still be good to be able to specify which tiles are deadly so that I can place hazards in the tile editor.