Lodging is probably the easiest and most attractive part of the Valley. Camp 4 (called Sunnyside Campground for some time) is considered a historic climbers campground, after the authorities tried to close it a couple of years ago, and the climbing community made itself heard to proclaim it a historic sight. Maybe a far cry, but it is rather fortunate that the campsite has remained as other accommodations in the park are rather expensive. Its main advantage is the price - $5 per night per person that is hard to beat anywhere today.
Unfortunately that comes with certain disadvantages. Camp 4 is a walk-in campground, meaning that you walk to the ranger's office in the morning, queue and get a site on first-come first-served basis. The inconveniene of the system is the queue that gets sometimes very long and slow - i had to queue from 7 in the morning to at least 10 to get a site sometimes. Another problem is the 7-day limit stay. It is only enforced during peak season, from May 1st to September 30th. From October to end of April there is no ranger and self-registration with envelopes in a box is applied, a very likeable system indeed!
When there are rules, there are always ways to circumnavigate them. First of all, there is no computer or other motorized way to keep track of the campers. Rangers rely mainly on the faces and current IDs (unfortunately IDs are required to register) to tell you to go away. After the 7th day you still have 2 days' notice, and on the 9th day only your tent gets confiscated. The usual way is to register on one person's name, spend 5-6 days in camp, get on a big wall for a couple of days to get forgotten by the ranger, come back and register on another person's name for a week, repeat ad infinitum and actually pay $5 per night for two people...Or not register at all - with 35 sights and 6 people per sight, there is little manageable way to identify the unregistered users. Use this advice at your own risk!
This is our tent at Camp 4, where we stayed registered for the whole 5 weeks without too much ado or any administrative problems:
Different lodging options are 3 other campsites ($20 per night per site) that have to be reserved in advance, Housekeeping camp and Curry Village (least expensive if not camping, $70 per night for the cabin), Yosemite Lodge (over $100 per night hotel), and the Ahwahnee Hotel (over $500 per night).
There are several possibilities for eating out. Our favorite price to quality mix was degnan's deli's large pizza with peppers sausage mushrooms. For $20 it makes a perfectly full stomach for two hungry dirt bags. The Mexican place at Curry Village has great Taco salads that can be eaten comfortably by two for lunch. There is a coffee and ice cream corner at Curry as well.
3. Transport and Maintenance
There are free hybrid shuttles functioning from camp 4 to Curry Village, around other stops in the park from 7 am to 10 pm, making it very convenient to live car-less inside the valley. To get there from San Francisco we used Amtrak (take BART from the airport to Richmond, board train there) to Merced and YARTS to Yosemite. From 9 to 6 there is also a shuttle going from the Visitor Center, stop at camp 4, to Manure Pile Buttress parking area - best way to access El Cap and Cathedrals if willing to walk or hitch hike.
There are wonderful hot free showers at Curry Village, later in the season they also have a pool there. There is laundry at the Housekeeping Camp. Internet (25c a minute) is available at Yosemite Lodge and Degnan's Deli. There is also free internet at special opening hours at the girls club library (ladies room) opposite the Visitor Center, a rather secret location that takes some time to locate!
4. Rest Days and Sightseeing
There is not exactly tons to do during the rest days. Visiting Ansel Adams Gallery is an intellectual pleasure. They also have a good collection of books for sale. There is also a free movie to see at the airconditioned theatre of the Visitor Center. Not far by, there is a cemetary, and as impressive Indian Museum.
Hiking is a more interesting option, though it's not exactly rest. Exploring and photographying various falls (Ribbon, Bridal Veil, Yosemite, Vernal, Nevada...) might become a hobby in itself, especially during spring time. Mirror Lake trail makes you leave the crowds of the shops just to find the hiking crowds. Little Yosemite Valley hike is definitely worth it, especially if you do not do the Half Dome descent at any point. It is also worth driving to the Glacier Point overlook when the road is opened, the views are fantastic. Mariposa Groove also requires hitch hiking to see the Sequoias. Toulomne Meadow is further down the road, that is usually closed until end of May.