There are only three hotels and a campground in the little Tikal village near the entrance to the ruins. Unless you have more than 2 days to spend exploring the region, I recommend staying near the ruins, as it allows you to enter early and stay late, and helps you avoid the Great Plaza and North Acropolis during the peak period when they are swarmed with day-trippers.
Although the ruins are officially open from 6am to 6pm, those staying at the site can sometimes finagle their way in earlier. Better yet, those staying at the site can have their admission ticket stamped, allowing them to stay inside the park until 8pm and a chance to catch both the sunset and moonrise from the top of one of the temples.
Note: Rooms are often difficult to get at the park, and making reservations is essential during the high season, which runs December through mid-April, coinciding with the winter months in most northern countries. There's also a mini-high season during the months of July and August. Some hotels charge their high-season rates during these months. Communication with the hotels here is difficult and undependable, and many reserve all of their high-season bookings for groups and prepaid package tours. Overbooking on behalf of these hotels is also not uncommon. If you're only coming for a couple of nights, book an organized tour to save yourself some hassle. If you plan to spend more time in the area and don't mind possibly spending a night in Flores or Santa Elena if necessary, you can probably make your arrangements once you're in Tikal.
Camping -- Just off the main parking lot at the site is a marked and designated camping area with a nice lawn and some trees for shade. You can also set up your tent on concrete pads under a palapa (open-sided structure). The camping area has simple shared shower and toilet facilities and a communal cooking area, but there's no phone. The campground charges Q30 to Q45 ($4-$6/£2-£3) per person for camping and use of the facilities. They also rent hammocks, which you can pitch under open-air palapas for Q30 ($4/£2).
Tip: If you plan on sleeping, or just taking an afternoon nap, in a hammock, be sure to get a mosquito net, which are available from most of the places that rent and sell hammocks.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.