I am doing that right now. what you need to do is look for programs that specify the ADN to BSN transition. the one I am involved with just requires that I take another 30 credits and I just take those as classes.
some are econ, pathophys, biophys, and another pharm class, but they are taken just as classes, and no further clinical work is required. however, I do have to pay for credit transfers to the other school.
also, there is an ADN to MSN program out, and if you are just looking to start, you may want to consider that and just get it out of the way