What program should i use to make slo -motion videos?

I have a Nikon D5100 and it can't do slo-motion by itself so I want to take a video in like 24fps and then use a program to edit the video and make it like 60fps. I don't want super slo-mo just normal slo-mo.

If you are recording in 24fps you can't change it to 60fps after shooting. The frames just aren't there. I have the same camera and i did some slow motion at 24fps. I slowed the footage down to about 60 percent speed and it looked good and smooth.anything under that will just look choppy and cheap. I use adobe premiere pro to do it. You can get a free trial of it on their website www.adobe.com.

Windows movie maker. Audacity can record audio though

AVS video suite is good - inexpensive, easy to use and contains about 20 different video/audio/image tools, including editors, converters etc.

http://avs-video-suite.org