I've never tried to play an entire maiden song.
But when looking through the guitar tabs, the easiest looking one I have seen is "can I play with madness".
The problem I have seen with maiden is that the guys (and out very own lovely gals) swap between rhythm and lead constantly, so theres no defined rhythm and no defined lead as such. All guitars play elements of lead.
I love playing the intro to "wasted years" and its very simple to learn.
I dont know how competant you are as a guitarist, I am self taught and a very poor player. But i have had some very nice comments on a cover version of Therapy? s screamager that I uploaded here.
Just learn what you can, the issue I find is a song is only as difficult as you make it. Anyone can play anything with practice.