Once you adopt him/her, I would take it to the vet. Even if it has had all it's shots and has been neutered, it would be in your and the cats best interest to set up a good relationship with a local vet. And to also get the cat checked for things that might have been missed.
You don't really need to worry about outlets, I've never seen a cat play with those, but sometimes they will chew wires, so just be aware of that if he starts chewing them. ALWAYS keep fresh water out for the cat. As for feeding, this is something your vet will be able to tell you based on the cat's weight and how malnourished he is. We feed our three adult cats each 1/2 cup of food in the morning and at supper. Kittens might need to be on soft food for a while, but I wouldn't spoil the cat on it. Also, don't let your vet talk you into feeding the cat science diet for the rest of it's life. The only way I can see a cat eating SD is if it has unrinary tract problems. We feed our cats the Purina Naturals. It's not cheap but IS a bit cheaper than Science Diet, plus there are NO animal by-products in it. This would be like chicken beaks, feet and other nasty stuff ground up and mixed with the food. Science Diet has this listed as the first ingredient, which means it's the major ingredient. Purina Naturals has NONE. Sorry, had to get on my soapbox for that...
Make sure you head to PetSmart and get LOTS of toys. Get some that he can bat around the floor and get at least one WAND toy. This is important. You never want to use your hands when you go to play with him. This will make the cat think your hand is a toy and in turn he will bite you everytime your hand is around him. This is why a wand toy is the best for interactive play, your hand is so far from the cat, he has no association with it. Also you will want to get a scratching post.
WalMart has these for cheaper than PetSmart. The cardboard scratchboards with catnip are also good to have around (they lay flat on the floor). These can also be found at WalMart. If you introduce the cat to the scratching post and board, you may be able to save your furniture. It works with my three cats. Most vets do not like to declaw cats because it is inhumane and I agree. You CAN teach them not to scratch on the furniture.
When the cat is doing something bad try this. Yell NO! really loud and take an envelope with the plastic where the adress is and hit it HARD on something nearby. Don't ever hit the cat. Trust me, the sound it makes will freak the cat out and he'll stop whatever he was doing.
Make sure you spend enough time playing with him. If you can't you might want to look into getting him a friend. Also I would keep him strictly indoors. Indoor cats lead a better life because they are not exposed to the elements and have less of a chance of being attacked by something. I leave the blinds up for the cats to look outside during the day and put the TV on the Animal Channel at a low volume. They seem quite content with that. They probably sleep most of the day anyway.
Ok I really can't think of anything else, but you can PM if you have any other questions. I grew up with cats and own three now so I've pretty much seen it all. I hope this helps!