Please excuse any grammatical/spelling errors. I typed this up pretty quickly to try and get my points down and across. So here goes...
One suggestion I have is addressing some of the more common learning styles that people have. Doing so may attract an even larger audience, and make your lessons/topics much more accessible (although they already are). Visual learners are the most common, while others include Auditory and Kinesthetic. But I'll give some examples of each style, and see what you think:
1. Visual learners (see): Though you have words, and some diagrams/imagery i feel you should incorporate more animation, diagrams, and pictures that illustrate your ideas. This would help improve the lesson that much more. Visual learners will understand certain concepts better if you have some animation of the code taking place. Nothing fancy that necessarily takes away from the lesson, but rather something that keeps my attention as you discuss each concept.
An example of this would be to maybe highlight the line(s) you're talking about because, although you're not necessarily speaking fast, i'm trying to process what you're saying, understand the concept, and see which part you're talking about as you discuss each line of code, all at the same time. However, I notice as i'm trying to understand each concept, I get lost because i then don't know where you are in the code all while you go through the material using programmer jargon which I am not completely familiar with. Imagine an advanced pianist talking about whole notes, quarter notes, octaves, vibrato and permutations all with just an image of some notes on a staff. It could get confusing unless you already know the material. So, maybe simply highlighting each segment (i.e. expression, argument, etc.) as you discuss it will help keep the viewer focused and in the right place.
2. Auditory learners (hear): You've pretty much got this covered. I think the pace you have is good. If you take too long, it'll waste people's time and they're better off reading something to move at their own pace. Speak too fast and you'll leave people behind.
3. Kinesthetic/tactile learners (Touch): Try to incorporate more interactive/hands-on activities. When you're discussing certain concepts that can involve the viewer, have them take part when they can put that idea into practice. Going through the first 5-6 lessons, I was hoping to be involved some how. For example, when discussing converting hex to decimal, give the viewer a number to convert, have them pause the video, and un-pause when they think they've got the right answer. Then show them the right way. Another example would be when discussing a particular programming language. Have them write a line of code in note pad, and show them what you have, to see if they have it right (i.e. writing a function using correct syntax (appropriate to the language being discussed), or an if/then statement that increments a variable by 1 up to 5, when you discuss conditionals). I just finished your Javascript lesson, and was hoping to be able to practice writing some code myself. Otherwise as soon as the lesson is over and I've watched each video, I have no idea if I've actually grasped the concepts taught. I know I can go and do this on my own and maybe your intention is to simply get me started, but it would be beneficial and practical to encourage the viewer to do it as they watch.
Those are just a few suggestions. I'm sure you're pretty much aware of the concepts above, so I hope it doesn't come off rude in any way. I really appreciate you taking the time to create these. It's helped me create a schedule for myself and really come back to each lesson, and go over the material. So, thanks a lot. I just figure if I can help, I want to. Though I used to know a little HTML, CSS and C++, I'm still a beginner, so I feel since some of these lessons are directed for people like me, I can maybe give you an idea of what I'm experiencing/thinking. With the small amount of knowledge that i have on the subject, I can just about keep up. But I can see where some may become lost without some other visual, auditory, or kinesthetic aides boosting their learning experience. Finally, I'm sorry I haven't necessarily given you specifics regarding the videos that I have already seen. I haven't had time to revisit them. But I'll try to go through some of them and provide specific lessons in the near future.
Hope this helps!
-Lev