I usually use File > Save As > JPEG Bitmap File. Bigger maps with sheet effects turned on crash for me sometimes as well (running Vista 64-bit OS with 4GB RAM). When it does that, I just shut down all processes except for CC3 and try again. Always works for me the 2nd or 3rd time, if not the first.

In addition to all the free sources already mentioned, you may have also seen others using Profantasy ad-ons. They have a few style packs with lots of symbols and also they sell "Annuals" that come in monthly installments - some of them have new symbols and styles to use.