One of the best ways to be self-sufficient is to have your own chickens. They can provide eggs as well as meat. However, before beginning the process, check on local regulations regarding the keepng of fowl. Once you are sure you can keep chickens without violating any local laws you're ready to move forward. A first step might be by answering the following basic questions on investing in chicks, coops, fencing and food.
What do you want from your chickens?
Other qualities - attractiveness, etc.
How many chickens per doz. eggs?
Typically you can expect each hen to lay one egg per day.
Which breed is most popular for eggs? 
It has been found that the most productive hens are hybrids.
Hy-line Brown *
Golden Comet *
However, the following heritage breeds are also popular for egg production:
White-faced Black Spanish
Rhode Island Reds *
Rhode Island Whites
Plymouth Rocks *
* These breeds lay extra large eggs
How long from chicks to laying eggs?
Depending on the breed you can expect eggs from young hens between 17-26 weeks.
How much room do they need? 
If you plan on having your chickens in a fenced area rather than allow them fee-range, then you can use the following for approximate calculations:
4 sq ft of floor space per adult chicken
1 sq ft of ventilation space per 10 sq ft of floor space
In addition to a coop, you'll also need to provide perches and nesting boxes. Perches will need to be away from the wall (12-18") and leave enough head room so they don't hit their heads when they fly up. Rounded wood is good for perches but not all wood is healthy for chickens so check on wood types prior to purchase.
How many nesting boxes per chickens?
You'll want at least one (1) nest box for each three (3) laying hens. A good standard size is 12" x 12" - but larger might be more comfortable. Line with hay.
Even if you have the best coop around - you'll still need to provide run space for the chickens. This can be estimated at 10 sq. ft. per large hen.
Where to buy chicks or chickens?
What type of feed is best?
This question is best answered by the breeder or hatchery personnel based on your needs - eggs or meat.
You may find these references helpful for more detailed information on raising chickens and building the perfect chicken coop.