1) Resin dust is not at all healthy to breathe. Use a particle mask to filter them.
2) Resin is soft and brittle. It sands easily, but be very careful about breakage, especially with thin parts.
3) Use a razor saw to cut the parts out and then whittle them down as necessary using coarse sandpaper.
4) I prefer to prime everything with enamel primer since I use acrylics. It seems to make the paint stick better.
5) Plan on using CA to glue the parts together. Styrene glues won't work.
6) Most putties for styrene don't stick that well either.
That's really about all I can think of. Otherwise it's a lot like working with styrene.