If you want to model rooms check out Sweet Home 3D: http://www.sweethome3d.com/index.jsp  It's free, quite easy to use and there are versions for Windows, Mac and Linux. The furniture included with it isn't the greatest, quite low poly actually, but you can always use the low poly models as a kind of "stand - in" then use a higher quality model for your final render or animation. The rooms you create can be exported in .OBJ format to use in Poser, Bryce, etc.. You can also import models in .3DS, .OBJ,  DAE (Collada) and .LWS format. As far as modelling furniture, I'd agree with the other recommendations you've been given so far. Good luck and have fun!