OK , I am also doing bloging and my blog is very much into Linux,Opensource and bloging trick tutorial.
These are the tips you should follow.It depends upon your requirement
There are many plugins also which can help you to make your blog good.
(1) Select the blog related theme. for eg. twenty twelve
(2) Select the them which supports Menu,sub menu (It depends upon your requirement)
(3) Almost all themes are supporting html5 ,it is good to select latest theme which also supports html5.
(4) The blog must be SEO friendly.Yoast is the one the good plugin which you can use it for SEO.
(5) Learn some basic of html and css atleast. As per your blog requirement try to add features yourself.It will help you to design your blog.
I have done a few changes in my blog , it is tutorial blog you can visit to my [Redacted - Please keep support on these forums]