Other than enabling Trim, is there anything else I should do with an SSD?
Yes and No. There's not a final answer on this. There are some basic things you don't want to do:


Never fill your drive, always try to have a minimum of a 20% of the drive free, SSD performance goes down fast when the drive is full or close to it.
Even with trim and whatever the OS does, at some point in 1, 2, 3, n years you might have to completely reformat/repartition the drive to gain some speed. This has been true on Windows Machines (I've seen it). My MacBook Air (1 year old) hasn't yet shown any signs of slowness. 
SSDs have a limited number of writes before they wear out. At some point blocks just stop working, so if you are constantly writing/deleting files, you're essentially wearing out your SSD faster than the average (however this number is huge, say it can last 10++ years under normal usage). One is expected to change the drive by then :)


I recommend you google around, there are multiple guides and advice pages. You will find this life hacker article relatively accurate and up-to-date. Bear in mind that technology in the future may change and the article (and this answer) may be rendered obsolete if, for example, SuperSSDs are created and they don't wear out or have a 1.000.000 years life-span :D