Get Answers from the OC Insiders
If you want to be on the boardwalk and close to where the rides and arcades are then you'll want to stay below 5th St. That's where the majority of shops, arcades, and amusements are on the boards. The boardwalk extends from the inlet to 27th St., so north of 5th St. to around 18th St you'll still find shops and restaurants on the boardwalk. From there to 27th St., you're still on the boards, but it's much quieter and very few if any shops or restaurants on the boards. That being said, there are still plenty of restaurants within walking distance and Jolly Roger Amusements. There is also a tram that runs the length of the boardwalk that you can ride for a small fee per ride.
Send for a free visitor's guide at www.ococean.com/visitor-guide or www.oceancity.org . These publications will help you get a better idea of how OC is laid out and where you might want to stay. And you can zoom in on the interactive map at www.ococean.com/maps . It will show you hotels and which ones they are if you zoom in and click on "hotels" on the left.
For some ideas of place to stay on the boardwalk take a look at this thread.