Just what the title says. I decided to improve my writing skills only for blogging purposes (for starters and no, it's not a part of new year's resolution). I am also not really good at writing (i.e. write a few paragraphs about simple topic/subject). I know that practice makes perfect, but I'm actually at the point where I would like to know what makes the beginning easier. Does reading books help writing in any way? I believe that my main obstacle for writing is inability to clearly express my thoughts. Will reading others' writings help overcome it?
Short answer: Yes.
Slightly longer answer: Yes, a lot! All reading is good, but not all reading is equal. All reading will help you absorb the effective use of written language, will increase your facility with words, will enhance your vocabulary, etc.
But if you're really serious, you should spend at least some of your time in conscious, directed reading in the genre of your choice. Fiction writers don't just read the masters, they study the masters. They break down the plot structure of great books in order to understand how things flow; they look at characterization and dialogue, and see how great authors use these tools to create compelling reading; they analyze the strengths and weaknesses of different books, and try to understand why the great books are great.
In your case, you want to become better at blogging, so you should not just read but study blogs. Find blogs you enjoy, and figure out why. Find blogs you don't enjoy and spend just as much time analyzing the problems there, so you'll know what to avoid. You want to work on clarity, so I would recommend looking at the structure of the blogs you find effective. You're not reading for content so much as you're reading for style and technique.
And, while you're at it, read everything else you lay eyes on. Writers read. Absolutely.
Absolutely! A blog entry is a short essay: studying (thanks, @Kate Sherwood!) essays, reading them closely, is always a good bet. The best essay writer I know is EB White: I reread White's work often. One Man's Meat is a rich collection of good writing.
Perhaps you're looking for a list of rules or suggestions. None surpasses Strunk and White, The Elements of Style.
"The Paris Review" has since birth published interviews with writers about the ways they work. These insights can help.
Everyone will tell you to read good writing.
I think that bad writing is as valuable. Sometimes, when I come across bad writing and I'm feeling virtuous, I ask why and how it's bad. Then I work to improve it. That exercise helps me greatly.
Please don't forget that writing is painstaking hard work: this answer took ninety minutes to write.
Finally, you must understand and embrace that good writing of any kind comes mainly from the heart.