To lower the roof pitch of your house use this cheat in the cheat window:
roofslopeangle [15-75] or
individualRoofSlopeAngle [15-75] - chose which number you want the pitch to be.
As for buildingg tutorials, I use the sims2wiki found here:
http://www.sims2wiki.info/wiki.php?title=Tutorials:Build_Mode_TutorialsI hope this helps. :smile: