k3b, brasero for CDs. To convert DVDs to mp4 handbrake. Those links doctordeere posted are good as well for video. For video editing I would refer you to Nixie Pixel on YouTube. She had lots of great videos about Linux including Audio and video editing.
You can try Ubuntu Studio which has installed by default a lot of audio and video editing software not included in Ubuntu by default
Unfortunately the video editing software on Linux is not up to snuff compared to Windows video editing software. Like I always say each OS has it advantages and disadvantages. One is not better than another. Each user must find and choose which OS suits their needs the best. I am a total non-believer in the windows vs. linux argument that some want to keep perpetuated. Choose what is best for you and be happy. No need to convince others your choice is the best. There are people on both sides of the linux/windows argument who are really only arguing to serve their own egos. Live and let live. If windows is your main OS that does not and should not bother me. I choose linux. Windows users can help me with windows and linux users can help me with linux. Lets get down to the basic reason this forum exists which is to help people with their problems. Last time I checked there is a Linux sub-forum in here. That sub-forum does not exist to tell people windows is better. It is there to help those experiencing problems with linux, which is their choice of OS. No one else can choose for them or infer their choice is wrong or that windows is better.