I am not sure what status code should I return to client. When the request has parameters out of range. My API support paging from page 1 to (let's say) 50. Which status code should server return to
page < 1 || page > 50
See http codes and explanation for example here: http://en.wikipedia.org/wiki/List_of_HTTP_status_codes
You should use some of the 4xx codes, because it's error on client side.
Let's use the 400 (Bad Request) status code. It's general error code, so it should be right.