Now that you have thought about why you will blog,
- determined your goal and audience
- set yourself up to build your network
- to comment on blogs
- to follow some blogs
- and actually set up your own blog
You click on the button to create a post and you have a blank sheet in front of you.
This is when you start to write.
Write as if you were talking to a good friend.
Be careful to avoid lingo that others may have trouble following, explain an acronym before using it.
There are countless writing resources available. You may have already found some in the course of your own research during Blogging 100.
For a quick sample, you could read and follow
Joanne Young who writes at http://confidentwriting.com/
Julie Roads who writes at http://writingroads.com/blog/
Patti Digh who writes at http://www.37days.com/
Christina Rosalie who writes at http://www.mytopography.com/
Robert Fulghum who writes at http://www.robertfulghum.com/
Ronni Bennett who writes at http://www.timegoesby.net/weblog/
For specific writing on blogging you can review
Liz Strauss on blogger best practices
Darren Rowse has Problogger tips
Chris Brogan who writes at http://www.chrisbrogan.com/
Seth Godin who writes at http://sethgodin.typepad.com/
The best way is to just start, try it, listen to feedback, adjust accordingly and go forward.
You will find your own writing style, your own voice. It is not likely to happen over night. Like anything, it takes practice. Have fun practicing!