Hey everyone. I could really use a little help. I want to get the most out of my workouts but I feel that I spend most of my time in the gym thinking "what should I do next". I've been off and on for a few years now. I don't have a problem getting to the gym I just feel lost. I really am not sure how I should split my days. I have 4 day's to work Monday, Tuesday, Thursday, and Friday. I have always used a 3 day split so having 4 days actually throws me off. I've thought about:
Monday - Chest Tris
Tuesday - Back Bis
Thursday - Legs Abs
Friday - Shoulders ??

But I'm not sure if thats a good split. Also, I really want to work dead lifts into my program but do I do that on back day or leg day? Finally, on back days I have NO CLUE what exercises to do. This past Thursday I did:
Lat pull downs 4 sets
Rows 4 sets
I know I'm missing out but I just don't know how to structure a good back routine (if that makes sense). Don't get me wrong I'm not afraid to bust ass at all I just need direction.
Thanks