Another Oak Parker here - pretty much lifelong, other than a stint in Hyde Park for a few years. As mentioned, there really isn't too much in the way of nightlife in the western burbs. There is a strip of bars on Madison in Forest Park that would be in between Oak Park and Loyola, but they're nothing special. There are some slightly more interesting bars/clubs further west (getting out to Lombard or Schaumburg) but those areas are not as nice as Oak Park in pretty much every respect other than nightlife. And if you'd be driving to go out (which you'd have to in those burbs), well, they're both somewhat reasonable drives from Oak Park. For true nightlife though, you would need to look for something on the north side of the city. Even downtown doesn't really have much of a nightlife in most areas.
As far as Oak Park goes, I pay $975 a month to rent a decent-sized 2 bedroom condo. I'm one block away from "downtown Oak Park" which means I'm one block from a movie theater, Borders/Gap/Old Navy/Whole Foods/many smaller specialty shops, a CTA el train and the Metra West line between downtown and Geneva, and at least half a dozen very good restaurants. And Mickey's, the greatest Greek-run fast food joint ever. Ever.
The Reader and Craigslist are indeed good sources for apartment listings. I'd also recommend the Oak Leaves though - that was the only paper where my current abode was listed, and it is the most popular local paper for the near Oak Park area so the classifieds get heavier traffic for this area than the other two sources.
http://www.pioneerlocal.com/cgi-bin/ppo-newsstand?paper2=op
Oh, as far as safety, you can't go wrong with most of the western burbs, other than those immediately around Loyola
Definitely pass on Maywood, Melrose Park and Bellwood. Westchester/Riverside/Brookfield have less in the way of safety concerns, but also much less to offer than Oak Park/Forest Park or the further western burbs. For living in the city, well, can't really give you any good general safety tips, other than avoid the west side. You'd have to check out each specific potential neighborhood individually, really.