Live plants process nitrates, and are generally good to have I think. (I don't have any). You still don't want to add water from one tank to the other, though, I don't think. No benefit, unless you were doing it for some pH-related acclimation purpose.
Plants will help speed up the cycle. They like ammonia more than nitrates. As long as you get low light plants,they are pretty easy to keep. Here is a link to give you an idea of what is good for beginners. On the left hand side of the page,go over to aquarium plants,then click on beginner plants. This is just to give you an idea of what is easy to keep. Then you can look around locally to see what your LFS carry.