In reply to Hans:
I would consider :
1) the nature of the area (lots of mechanical uplift, very little, mainly big mountains or principally technical rock routes, etc)
2) what my and my partner's objectives are (i.e. are there any 4000m peaks I haven't climbed there, and how can I persuade/fool/bully my partner into thinking that they want to climb them as well)
3) specific routes, including descent/escape routes/other bail-out options
4) competence/experience/fitness/aclimitisation for routes/area
5) weather/conditions leading up to the trip, also those forecast for the trip time
Important principle - do NOT get too route or peak fixated. If something just isn't there, don't try to desperately force it, that way lies coming away with nothing or getting into a desperate epic, or both. If you can't do what you want, want to do what you can, and enjoy it as a good day out in the mountains or even valley cragging.
Lots of sources of information these days, from webcams, weather forecasts (obviously), websites like CampToCamp, etc. CampToCamp is especially good as it contains recent descriptions of the route, from people who have done it. If anyone puts a description in of course, so it is worth making the effort to do that for a route you have done, to help someone else. Still look at guidebooks of course, which are mostly MUCH better than they used to be. Get advice if you can, e.g. ask about specific routes/areas here beforehand. Phrase your request right and people will be very helpful, sound like a smartarse and you will probably get some offhand responses.