accessing Steam games and acheivements offline

I'm going on a trip soon, and I want to bring my laptop on the plane so that I can play some Steam Games. Is it possible to access Steam games offline? I have a feeling that it is, but I want to make sure.
 
Also, can I get Steam achievements when playing my games offline, do I get them synched next time I go online, like with the PS3, etc.? 
 
edit: can a mod please move this to the Steam forum. I tried, but couldn't specify a specific forum to attach it to for some reason.

You can play steam games offline as long as you've downloaded and ran them before going offline. I'm unsure if you can get achievements offline, though. If worst comes to worst, you can always force ones you achieve to unlock with Gibbed's Achievement Manager (though obviously using that tool is only recommended if you're willing to suffer the rare and improbable consequences)

You can run them offline. However i am not sure about gaining the achievements offline myself.

You have to run steam in Offline mode to use it offline. Make sure that offline mode works by pressing "go offline" in the menues.
And you can't unlock achievements while in offline mode, and don't use any achievement managers, because they can in worst case ban you.
 
https://support.steampowered.com/kb_article.php?ref=4462-UIOB-0425
 
https://support.steampowered.com/kb_article.php?ref=3160-AGCB-2555