Eagle Mountain Lake is a lake that produces all species in both quality and quantity. It's all about location, and there are so many locations it's hard to find a starting place.
Go to any Marina and ask a few questions. I'd simply suggest you pick any boat ramp on the lake and find some drop offs. My best suggestion would be across the lake (East) of West Bay Marina. It is shallow and no private docks and about 20 yards from the bank there is a drop off to about 20 ft. Fish parallel (North to South) and troll slowly for the best opportunity to catch crappies.
Good luck.