Help: interior painting questions

[AstaMar]

Hi all,
I just bought a house and want to paint the interior. The previous owners
painted a large portion of this house with an oil-based paint, which looks
awful. Also, they attempted to hang wallpaper in several rooms, and didn't
do a good job, either. Here's the questions I have:
1) Since I am going to paint during the winter, what is the minimum
temperature I need to maintain in the house for paint to dry up ?
2) What kind of a primer should I use on these oil-painted walls ? Has
anyone had any bad experience trying to paint over an oil-based paint with a
"regular" one ? Any good recomendations as to which brand I should use ?
3) How hard is it to put ceramic tile on the floor ? Has anybody tried to do
it himself ?
I would greatly appreciate any input on this . *Please* email your reply to
eg...@bigfoot.com