well i always say start the easiest way. check your library for any TPBs or compliations.
I HIGHLY recommend New X-men "Childhood's End" (5 volumes) which showcases the talent of writer Chris Yost. It picks up right after Decimation and leads up to the return of Magik! I also recommend X-men: Endangered Species, Messiah Complex & its follow up, 2nd Coming. Those (imo) will bring you really close to right up to speed with what the X-men have been up to.
AND even though its a few years old now- because i think YOU'd enjoy it....see if you can get Astonishing X-men: Torn (by Joss Whedon). I was not a fan of his treatment of Shadowcat during his run on that title, but this particular story I think you'd like. Kitty essentially is the X-men's failsafe as the White Queen has seemingly reverted to her Hellfire Roots as Kitty always knew she would.
You can always search Wiki for any Marvel title/group and they'll have all their major storylines/crossovers documented and then try searching for the collection of those at the library. thats how i started getting back in. plus...in the wake of people like grant morrison and brian bendis, i REALLY attention to whose WRITING because Marvel stupidly gave more deference to artists over writers starting in the 90s and thats why so many of the books have declined and why they lost such mega talent like chris claremont for years.