Hmmmm, I don't really think there is a specific RDA I could recommend as a "beginner" RDA. I personally feel that each RDA is equally as painful to build, unless it was just designed horribly, then it's not worth getting.
I personally always keep coming back to my Trident V2 RDA. It just does what I need it to do. I paid only about $30 for it I think. It's a clone made by Tobeco. It's kind of annoying to build on but I get great flavor and vapor production. But I am a sub-ohmer so that is how I mostly use it, and with very little airflow. It has adjustable airflow and I vape really weird and this RDA allows that. I'm prob the only one vaping at 0.3ohms with the airflow of a clearo cut as low as possible. I have to change my wick daily because of the way I vape...I have used it at over 1ohm a few times and it still works great....
If you have never rebuilt, ever, I would suggest getting the Smok Octopus (I think that's what it's called). It is definitely the easiest to build on, but like I initially said, every rebuildable has quirks that you need to get used to before they become "easy" to build on. It just has 2 little posts that you screw up and down with your fingers so you can get used to inserting leads without having to use a screwdriver or allen key making things awkward. It's only like $10-$15 too, and then you can figure out if you even like rebuilding at all. If you get it just let me know and I can give you some pointers...