I have a Nikon D5000. I have had it for about 3 years or so. Of late I am having problems with the shutter release button (have to really push it down hard) before it takes a shot. Then on other occasions it works fine. When pressing it down the little "hour glass" appears then back to information screen and is repeated. If anyone has had similar problems, how did you resolve it? I am thinking of having it repaired, but I am trying to research the issue to see if there is anything I could do myself to fix it.
Considering it has already reach a 3-years, check if it has already reached its actuation count limit. Every DSLR has its actuation limit of more or less 100,000. Meaning if you have already taken 100k shots, you have reached the life span of its shutter. But nothing to worry, just bring it to the Nikon service center, then they will replace it and it will be good as new, and the shutter count will be reset.
To check if you reach the limit, upload a picture of your latest shot to http://www.myshuttercount.com/