I found it a steep learning curve too! so here's a few more to add to lyrah's list:
CD - cycle day
DPO - days past ovulation
OV - ovulation
DTD - do the (baby) dance
POAS - pee on a stick
OPK - ovulation predictor kit
HPT - home preganacy test
an evap is a line you get on OPKs/ HPTs that isn't a test positive they are normally grey/ offwhite line where the test result should be but I'm sure I've seen some reports about faulty test batches that have coloured evaps giving false positive results.
http://www.peeonastick.com/hptfaq.html#7 has a more technical explanantion!!