Ultimately, the right length for a video is just long enough to get all of the information across without padding your video. Don’t make a video longer just for the sake of making it longer because you’ll lose viewers. But you do want to develop your video content with longer videos in mind. In general, videos from 7-15 minutes tend to perform best.
There are a variety of free and open source video editors available online. Many of these contain the same features or similar features as expensive professional editing software. For beginners, feel free to get acquainted with the free software that comes with your computer. For Macs, iMovie and for Windows, it's the Windows Movie Maker. After you become acquainted with these interfaces and the technology behind them, you can progress to more complicated and more powerful software.
Branding your channel helps bring a consistent experience to your viewers and subscribers on YouTube that they would see similarly reflected elsewhere. It’s important to let each marketing channel have its own feel, but also be tied together with other channels as well. Highlighting your most important videos on your channel, alongside your other social networks is a helpful way to help flaunt your digital savvy and help make it as easy as possible for your online advocates to connect with you wherever they’re active.
Add channel art. This is an image that is seen at the top of your channel page. YouTube will show examples of how the image will be displayed on the website, a TV, or a mobile device. Try to put the focus of the picture in the middle; when your channel is viewed on a mobile device, the sides of the picture will be cut off. You don't want to be left with half your face!