The video editing software that comes with your computer or digital camera may be all you need, but here are some more 'free' options for you to choose from.
Avidemux - Avidemux is a free video editor designed for simple cutting, filtering and encoding tasks. It supports many file types, including AVI, DVD compatible MPEG files, MP4 and ASF, using a variety of codecs. Tasks can be automated using projects, job queue and powerful scripting capabilities.
Blender - Blender is the free open source 3D content creation suite, available for all major operating systems under the GNU General Public License.
Jahshaka - Designed for editors and other professionals involved in digital content creation, Jahshaka is a post production suite that will ultimately include modules for video and audio editing, compositing, animation, visual effects, graphics and paint. Hardware accelerated using OpenGL and built using cross-platform technology, the software runs equally well on Windows, Mac OSX and Linux. Under development since January 2000, the project has had more than 500,000 downloads to date.
SolveigMM AVI Trimmer - SolveigMM AVI Trimmer is a free video editor to allow you to AVI movie cut extremely fast and lossless. This freeware AVI editor software is small, smart, easy to use and involves no encoding/decoding processes. Video enthusiasts use AVI Trimmer to cut commercials, cut video files or edit video for YouTube. AVI Trimmer solves annoying out of sync problem. It operates with all known types of AVI including DV AVI type 1 and 2.
Videopad - Video Editor Software
Virtual Dub - A powerful freeware video editor with lots of features, including a choice of compression codecs, splitting, addition of audio tracks
Wax - Wax is a high performance and flexible video compositing and special effects software. The idea for Wax is to be very general purpose and flexible in video compositing and effects, so that you can compose your dream video sequence with ease everytime.
Zwei-Stein - Zwei-Stein 3.01 is a freeware non-linear, non-destructive video compositing and editing system which offers many advanced features unavailable elsewhere.\r\n\r\nWith Zwei-Stein you can edit up to 256 video, audio and still image clips, each with up to 64 effects chained serially. Cropping, panning and custom effects are easy with automatic key frames.