Was fairly easy to pick up the basic mechanics but it takes a while to learn all the minutiae that makes the
BRB so bloated. Start with the core gameplay mechanics and slowly add on more mechanics and special rules. Trying to take everything in at once was daunting for me and I'm a fairly quick learner.
http://www.dakkadakka.com/dakkaforum/posts/list/0/597998 is a great tool for learning the game (or just in general to remember everything) as you can quickly reference special rules without having to flip through the
BRB a million times trying to learn the game.