Morel hunting in Maryland
I'm not aware of a morel-only hunting club. The Mycological Association of Washington (mawdc.org) is probably the closest mushroom hunting club near Baltimore. A great group of people and you'll learn not only about morels but also the many other edible wild mushrooms commonly found in the area and fungi in general.
While I think it's pretty easy to identify morels, I strongly recommend you go morel (or any edible mushroom)-hunting with an experienced person. Sometimes what you see in books is different from what you see in the field and going with an experienced person will be beneficial. I'd also recommend you purchase the Audobon book of mushrooms which is a standard in the field.
As far as I know, there are only a few deadly mushrooms around here- others will just cause tummy issues. Even perfectly edible mushrooms may cause gastric upset because of the earth in which they grew.
I've heard farmers markets carry fresh morels though many believe dried morels taste better than fresh. In the DMV, the season typically starts in mid-April in the lower elevation areas and goes on to about mid-May in the more mountainous areas.