I have been working in animal rescue for over 10 years now, and would happy to talk to you in PM if you have further questions. I have fostered dogs, worked in animal shelters and even boarding facilities, and am currently the Volunteer Coordinator for a local animal rescue.
For food, it really depends how much you want to spend on your pets. I use wet food to mark special occasions - it is unnecessary for a daily food. Brands like Walmart or a grocery-store brand tend to be the worst quality foods. Science Diet is also a pretty low food unless your animal has a specific allergy that requires it. Iams and Purina are okay foods, but contain a lot of corn and meat bi-products, which have no nutritional value (a lot like the bread served at a restaurant, it exists only to fill up the animal, not to provide any vitamins). Nutro is a step up from Iams or Purina. Blue Buffalo, and brands like that tend to be top of the line. Don't judge by price though, as that can be misleading; judge by ingredients. A really really good food will be made in the U.S. (to avoid any of the poisons the Chinese factories accidentally have added to the foods), and should contain meat (such as chicken or lamb) as the first and primary ingredient. Anything that lists "chicken meal" or "chicken biproduct" lowers the quality and nutritional value of the food, and corn is also an ingredient that has no nutritional value for a dog or cat. Of course, the top quality is to cook for your pets yourself. I do not do this, and if you did decide to, you would need to speak to a pet nutritionist to make sure that all of your pet's nutritional needs are being met.
It is usually good to feed a dog at least twice a day. Larger dogs that are prone to Bloat may need even more meals. Talk to your vet about risks of Bloat and feeding schedules.
If you are inexperienced with pets, I really recommend you start with one at a time. Puppies and Kittens are often a lot more work than dogs and cats, and if you don't know what you're getting yourself into, you might find yourself overwhelmed with two pets to train. I have 3 dogs and 2 cats (all rescues) and we have built our family up over the years. There is no need to get them together in order to socialize them - if you get a dog, make sure you have a trainer to help you introduce the cat at a later date. Remember that not all dogs (or dog breeds) get along well with cats, and consider that when picking one out.
Good luck.