Congratulations on your new arrival.
The first bit of advice I must give is to take your new kitten to your vet and get him/her checked over to make sure all is well. Added to this your kitten is at an age when vaccinations need to be started.
A vet will also be able to give you advice about what foods are best for the kitten and when worming etc should be started.
Another consideration is neutering/spaying of your new pet. This can been done from 5 months. Again your vet is the best to advise you on this. However there has been a study which suggests that cats spayed/neutered before 12 months were longer, taller and more affectionate than those after 12 months old.
Regarding feeding of your kitten, again a vets advice is important. Although your kitten is 7 weeks old, are you sure it is fully weaned from it mothers milk and is happy to eat solids without it's mother milk supplement. If so dry or canned food specially formulated for kittens should be given.
Don't give your kitten cows milk as it can make it ill. You can get mothers milk replacers from reputable stores or of course from your vet.
Although a visit to the vet costs money, in the long run it is a worthwhile expense. Most of the questions you have can be answered on the first visit.
My advice is always to get what you need from the vet. For example you can buy worming tablets over the counter but I have always found those supplied by the vet are much safer and reliable.
The same applies to de-fleeing etc. I have found that over the counter remedies are far less effective than the ones the vet supplies. Also the vet can recommend a safe de-fleaing agent to use.
Below are a few websites I am sure you will find very helpful. Vaccines & Vaccination Schedule for Cats & Kittens Worming your cat Early Spaying & Neutering of Kittens How to Care for Your Kitten
Good luck and may your kitten have a long, happy and healthy life.
May I wish you both the happiest and healthiest 2007.