I hope u r still a beginner in designing the website.Everything on your website is unorganized and the alignment of the blog is not nice.Just try to workout more on your blog so that by working again and again you can design it in a better way.
You will get better over time. Expand your text to full width and also work on your spelling. Download a dictionary or go to dictionary.com often
its ok .... design is good according to your subject. did you made this blog to write about history of computer only.i have a question are you getting any revenue from you tube.
your banner need some work, color scheme looking good, keep working, add some effective photo and animation
no.. thats not good!! you need manage your content very well, just fixing some css, then it will be goog!!