Introducing two cats?

[Fred Mattison]

I have a 2 year old fixed female cat and my room mate is bringing over her 4 year old fixed male cat what do you think will be the best

 

[CanadianPerspective]

Simple, just follow expert guidelines, here are two links that will be helpful...
http://cats.about.com/cs/catmanagement101/a/introducecats.htm
http://www.ehow.com/how_2326014_introduce-new-cat-old-cat.html

Difficulty: Moderately Challenging
Instructions

Things You'll Need
Two spaces with a door separating them, and space underneath the door.
Two sets of food and water bowls.
A new litter pan
A few days to help and observe.
1
For the days before adopting your new cat, remember to give your old cat lots of extra love.

2
Purchase some new things for the new cat: water and food bowls, litter tray, maybe a new scratching post.

3
Bring the new cat in a crate into the house. Put the new cat in a room or section of the house that has a door that you can close. Make sure the new cat has water and food in the new bowls and a new litter tray. The new cat should stay in this room for at least a night, probably a day, maybe more - depending on the cat.

4
Allow the cats to sniff each other through the door. The new cat will adjust to the old cat's smell in the room it's in. The old cat will get used to the new cat's smell under the door.

5
After an evening or a day, switch the cats. The new cat will go into the space where the old one was and vice versa. Probably the old cat will be a little upset with the new smells in a stronger concentration. Give them a day or a night in the new spaces. Make sure they're both getting lots of love and attention from you.

6
Put the new cat in the crate and open the door that's been separating them. Allow the old cat to check the new cat out. The crate provides a safe boundary for them both, but allows them to finally see one another. They may hiss and talk to each other in not friendly ways, but this is a slow process. If the tension gets too high, separate them and close the door again.

7
In time, the two cats will grow accustomed to each other. Usually, this happens in less than a week. For the first week or so that they're together in the house, leave them in their two separate spaces while you're out of the house, but bring them together when you're home.

8
With time and patience, your two cats will grow to love and appreciate each other.

 

[Twinx]

Let them sniff eachother and if they hiss at eachother just leave them alone. after a while if they are around eachother they will get used to eachother....hopefully. thats what happend with my two cats twinky and tommy.

 

[Audi]

If either of them are really violent put them on either side of something clear, so they can look at each other and hear each other but not touch. They are both spayed/neutered so they shouldn't be that violent but just introduce them and let "meet" each other and watch them closely.