One of the most common tools for uploading is Tube Mogul, which let's you upload one video and it will get distributed to a batch of the top video sharing sites. TubeMogul.com | In-Depth Tracking, Analytics for Online Video | Web Video Syndication
I have at least 3 accounts on at least 20 different video sharing sites also, which I'd be happy to use to upload any shorter videos you create and want to get 'out there'.
With Youtube specifically, there are some basic things for effective marketing which include:
1 - Ensuring that you include the full url that you want people to be able to go to in the description section (so that it appears as a clickable link next to the video.
2 - Youtube allows you to add annotations after you've uploaded a video, these are good for call outs at particular points in the video, and also for enabling adding a clickable text link on the video itself (usually at the beginning and/or end of the video when you want people to be able to take your prefer action). It's worth testing these to see which get the best conversions.
3 - Youtube provide analytics for the video which are worth checking regularly as they show how much and which parts of the video get viewed most. (obviously those are the parts you would tend to focus on having a strong message or a call to action)
4 - Youtube allow 'tags', effective use of the tags ensure the video gets found more often and more easily.
5 - linking to specific parts of the video. - If you look at the end of a Youtube url you will often see something like "#t=31m08s" on the end of the url? That link will take you 31 minutes and 8 seconds into that video, so if you're referring a person that you want to see a particular piece of the video, this is a good way to do it.
6 - The video title you upload with is just about the biggest influencing factor for the number of views it gets.
7 - Thumbnails - Once your video's been processed, three representative video thumbnails will be generated automatically by the system. Once these thumbnails have been generated, you can select one of the them as your video thumbnail. I have seen a pattern in how far into the video the thumbnails are taken from and considered testing having certain content at those points, but not sure if that's too far to go. However, the thumbnail is something people often look at, so worth picking the most suitable one, and testing others. There are tools that will let you pick your thumbnails, so that might be better since different video sites do this differently.