Although Disneyland offers several great "official" hotels, they can get very expensive. Similarly, the restaurants in the resort charge a great deal for their food. If you are on a budget, you can get around this by staying at a different hotel nearby. Anaheim offers a number of great, inexpensive places to stay which aren't affiliated with the park. Some are within easy walking distance of the ticket booth, which means your won't even have to drive to get there. In addition, you can save money by bringing your own snacks into the park--particularly water bottles, which you'll want while walking around on warm days. Sandwiches and similar snacks can stretch your budget further and let you concentrate on the rides rather than waiting in line for food.
Disneyland Resort has two distinct parks--Disneyland proper and California Adventure--which both require separate admission to enter. The good news is that they are within about 100 yards of each other (unlike Walt Disney World, where traveling to different parks requires a little jaunt). Most people prefer Disneyland to California Adventure, but if you have the time, you may want to visit both. Disneyland often offers two-for-one tickets, whereby you can visit both parks for a single admission, provided you go to them on different days. Look for it, or similar deals which can help you enjoy every corner of the resort.
Crowds ebb and flow with the seasons at Disneyland Resort. The summer months (June, July and August) are particularly bad, as are Christmas vacation and spring break (mid-March through late April). The off-season, on the other hand, makes for a much more pleasant visit, with short lines and a corresponding lack of stress. January and February, and August through November are very good times to visit. Weekdays tend to be less crowded than weekends as well, though you may have to forgo certain benefits, such as nighttime fireworks shows. If you can, try to schedule your trip when crowds are light. Otherwise, plan to spend several days at the park in order to go on every ride you want.
Everyone has their favorite rides at the Disneyland Resort, but a few stand out as particularly special. The "holy trinity" at Disneyland consists of the Pirates of the Caribbean, the Haunted Mansion and the Indiana Jones ride--every visitor should make time for them. The rides in Fantasyland, based on Disney's classic movies, are high priority as well. If you like roller coasters, Disneyland has three--the Matterhorn, Space Mountain and Big Thunder Mountain--along with a fun VR ride based on "Star Wars" and a water flume ride called Splash Mountain. The remainder of the park can be enjoyed as time permits.
California Adventure has fewer "must-rides," though there are a few. Soarin' Over California is a lot of fun for the whole family, as is a unique ride based on a boardwalk shooting gallery and featuring the cast of "Toy Story." The Muppets 3-D experience is a hoot--especially for fans of Kermit and his friends--while those looking for more exciting rides than Disneyland should definitely head on over to DCA. California Screamin' is a first-rate roller coaster and the Twilight Zone Tower of Terror sets a new standard for scares.