Where to stay
The vast majority of hotels on Oahu are located in Waikiki. With the exception of the Marriot Ihilani and the Makaha Resort located on the leeward coast; the Turtle Bay Resort on the North Shore; and the Ala Moana Hotel in downtown Honolulu, you are looking at a stay in Waikiki.
The two key deciding factors on choosing a hotel in Waikiki is cost and location. Waikiki hotels can be very expensive. If you are renting a car, be sure to ask if there is an additional charge for parking. Some of the cheaper hotels let you park for free, while the more expensive ones can charge up to $20 per day (go figure).
The "main action" of Waikiki takes place along Kalakaua Ave. That is where most of the stores and restaurants are located. The Diamond Head end (near the zoo) of Kalakaua has the best Waikiki beach experience. I would not pay a lot extra money to get a hotel that is directly on the beach. Here's a well-kept secret: the beaches in Waikiki are really not that great. While the previous sentence may cause some anguish for the Hawaii Visitors and Conventions Bureau, it's the truth. The sand has been eroding for years and many hotels that claim to be on the beach, do not have that great of a beach in front of them. (except for the Hilton Hawaiian Village, which has a great beach, but is pretty far away from the "real action" of Waikiki). The point is, don't anguish over whether your hotel is beachfront or not. You can easily walk to the beach from any of the hotels in Waikiki.
Your best bet is to decide how much money you want to spend and then go to a site like Tripadvisor, plug in the dollar figure, and read the reviews. Hotels are always changing and a user-review site like TripAdvisor can keep up with it. You can also get information here on B&B's around the island. Check out Waikiki hotels using TripAdvisor.
Another way to slice the hotel pie is to look at a map-based source. This will give you an idea where the hotels are located. Google Maps is a great way to get a list of all of the Waikiki hotels, links to the official hotel websites, photos, reviews, and other information. Check out Waikiki hotels using Google Maps