Here's some info I found on the interwebz about introducing cats to each other. Hope it helps and good luck with your new little'un (looking forward to pics)!
"Although sometimes cats will get along swimmingly in just a couple of hours, you should not be surprised to have a battle on your hands if you try to introduce your new cat too quickly. The time you spend on this all-important process will be saved exponentially by not having to break up conflicts every day. Also, the first couple of weeks can set the tone for the relationship for a long time to come, so "getting it right" the first time will save a lot of hassles later on.
The Steps to Take
Set up a comfortable "safe room" for New Cat. Put her food, water, litter box (not near the food), scratching post, toys, and bed or other sleeping mat there.
Expect a great deal of "hissy-spitty" behavior through the closed door from both cats. This is natural and normal; they are just starting to explore their "pecking order."
Scent is very important for cats. Let each of them smell the other indirectly, by rubbing a towel on one and letting the other smell it. They will soon accept the scent as a normal part of the house.
Once or twice, switch roles. Put New Cat in the normal living quarters, and let your resident cat sniff out the new cat's Safe Room.
After a day or so, let the two cats sniff each other through a baby-gate or through a barely-opened door. Gauge the rate at which they seem to be acclimating to each other.
When you think they're ready, let them mingle under your supervision. Ignore hissing and growling, but you may have to intervene if a physical battle breaks out. Again, take this step slowly, depending on how quickly they get along. If they do seem to tolerate each other, even begrudgingly, praise both of them profusely.
Make their first activities together enjoyable ones so they will learn to associate pleasure with the presence of the other cat. Feeding (with their own separate dishes), playing, and petting. Keep up with the praise.
If things start going badly, separate them again, and then start where you left off. If one cat seems to consistently be the aggressor, give her some "time out," then try again a little bit later.
The introduction can take from two hours to six months, so don't be discouraged if your cats don't seem to get along well at first. Often the case is that they will eventually be "best buddies."
Factors to Consider
If you are thinking of getting a kitten to keep an older cat company, you might want to consider two kittens. They will be able to keep each other company while the older cat learns to love them.
If you already have more than one cat, use the "alpha cat" for preliminary introductions. Once he/she accepts the newcomer, the other resident cats will quickly fall in line.
Lots of snuggle-time and attention is indicated for all cats concerned during this period. Remember, the prime goal is to get them to associate pleasure with the presence of each other.
If possible, ask a friend to deliver the new cat to your home, in her cage. You can act nonchalant, as if it's no big deal, then later let your resident cat(s) think it's their idea to welcome the newcomer.
With patience and perseverance, you can turn what might appear at first as an "armed camp" into a haven of peace for your integrated feline family. Congratulations on giving another cat in need a permanent home!"
