How to introduce new dog to resident (and once stray) cat?

I took in a stray cat about a year ago and have been wanting to get a dog for a while. My cat is very well behaved and loooooves other people, however he gets defensive in the presence of other animals (the only experience he has had is through the front door or at the vet in his carrier), but he will hiss a little bit and get a really poofy tail when he sees them.

I have been wanting to get a dog for a while and I’m hoping you guys can share with me some pointers on getting a new dog acquainted with my cat, or if any of you have success stories about a similar situation it would be greatly appreciated!!!!