Mine is 15 weeks now, we got him at 6 weeks.
Start slowly by introducing kitten to one room with nice food available to entice them out of box. Let them come out of box in their own time and explore with minimal noise/attention and let them come to you. Try to block off all access to small spaces before hand so they don't bolt down the back of something and get stuck.
Make sure that you show them the litter tray, they may try to pee elsewhere (plastic bags a favourite) if they do gently push nose in it then place them on the litter tray. They will soon get the hang of it. I recommend Sophisticat antibacterial cat litter as it really disguises the smells and doesn't stick to their feet or fur around their bottoms (we have tried several). Put several liners or a black bag in the litter tray to make it easier to clean out.
The kitten may return to the box as a place of safety to sleep or you can have a designated kitten bed/box and place a soft blanket/towel in their with an old teddy for company.
We kept ours in our bedroom for the first two nights and he slept on the bed by my head (also had food and litter tray in the room on lots of newspaper). Once he was more confident we moved food and litter tray to kitchen.
Get some toys, mouse on elastic attached to fishing rod is my kittens favourite, small plastic balls, foil balls, feathers on a string and play with them. Do not encourage them to bite your hands or you will set up a pattern of behaviour that will hurt you as their little teeth grow.
Feed 4-5 times a day at first, can reduce frequency after 3 months, but offer more food at each meal.
9 weeks for first vaccinations, 12 weeks for second, also get them wormed and de-flead, booster vaccs at 12 months. If you are neutering around 6 months best time (vets won't do it before 4 months minimum).
Oh and Argos do a good basic starter set with litter tray, scratching post, kitten bed and cat box for about £30, although you may find that they grow out of litter tray, bed and cat box eventually.