Bringing home a feral cat can be much more difficult then a domestic.
Arrival of the new cat
If the kitten / cat is confident enough allow them to explore. Show them a smaller area where they can feel safe with their food, water and a litter tray. When they begin to settle try to slowly introduce yourself with a soothing voice, stepping back if they become distressed / very nervous.
If the kitten / cat is not confident enough to see the home and hides it is best to set up a cage similar to those they've used before. The cage must be large enough to have their food, water, bedding, scratching post and kitty litter away from each other (it's a rather large cage). Keep this cage in a quiet room where you will be so they can get used to you in a secure setting. After a couple of days try propping the cage door open so the kitten / cat can explore but can run back to the cage if they're scared. Try to get close to them over time and get them to take treats such as chicken or ham from your hand
Talk to them in a soothing voice from a distance if they are nervous of you - leaving them alone if necessary. Try to get closer to them over time with a aim to allow them to sniff your hand and hopefully accept human touch. After you have made successful introductions with the cat spending time with them grooming, playing and just being with each other is the best way to continue bonding.
The Great Outdoors
It is advised to keep your new cat inside until they adjust to their new home which can be months or longer depending on the cat. This is to stop them trying to get back to their old owner, shelter, etc.
The Horror of the Vacuum
Hoovers are loud and startle most cats - make sure all the hoovering is done before the cat arrives and avoid doing anymore for a couple of days while the cat settles.