I had Shimano SPD 520 pedals and Bontrager RL MTB shoes for a year and liked 'em good enough. They definitely made a change to my riding, and did add some enjoyment to it. That said, I'm now back on big BMX platforms with tennis shoes and just as happy. I'm not sure I'll go back to them.
I'd also echo not using them your first year riding. Just get used to the motion, the weight shifting and all of that before you go clipless. They will make a difference, but it's not as extreme as say - proper fit.
Anyway SPD's are very easy to get in and out of as long as you practice and set the tension very loose.