Have your hubby, bf, significant other bring the new kitty in the house. This way your first kitty won't think you're the bag guy.

Put new kitty in spare room with litterbox, food and water. Rub him down with an old towel and let first kitty smell his scent. Do the same thing with the other kitty, rub first kitty down with towel and let new kitty smell his scent.

Keep new kitty in spare room for a week or so, leaving a light or nightlight on and a radio with classical music. Both cats will know that they are there and will sniff each other under the door.

If you have "baby gates" or safety gates as some call them, you can put those in the door way on top of each other (this is after the first week) so the cats can see and sniff each other, letting them get better acquainted. After a while, once YOU feel comfortable that it's okay to let new kitty out, let him/her out and supervise their interaction.

There will be hissing and growling. Just let them do their thing. If there is any bloodshed, spray water on them and put new kitty back in the room. Keep letting them interact. Eventually it'll all come together. Just remember that the house is kitty #1's domain. Shower your first kitty with love and assurance that he is still #1 cat.

Time and patience are the key. Good luck and please keep us posted.