If I was advising someone on what martial art to start training in, it would probably be judo. The balance skills of judo translate into any skills you do afterward.
If you're into ground work, there's plenty of that in judo as well, and the techniques are very adaptable to self defense or other arts. I personally always enjoyed judo training and found everything in it to be easily researched and there is plenty of documentation around about how to do techniques correctly without depending on everybody else's opinion. They either work or they don't. If they don't, you get to stand back up and start over.