Hmmnn... usually somebody planning to start a blog already has ideas. They are passionate about something and can't wait to start writing.
Search for your favorite topics to get ideas.
Do blog searches for those topics. There is lots out there.
Once you have some ideas, write several blog posts in a word processor. Write them well, edit them a few times, get them ready for prime time. If you can't write several posts in a word processor, there is no point going through the trouble of setting up a blog.
If you are confident you will be able to blog regularly without running out of ideas, try a free blog on Blogger. WordPress is also popular, but it seems to be a popular target for hackers, and you may not want the hassle of administering a site and all the behind-the-scenes work. There are many other options too.
that depends on what kind of blog you want to have, if you want a personal blog, you can take ideas from your day to day life anything about you, anything hapenning around you, or if you want to have a blog about a particular category of your interest you can search for ideas in the net and you will get many, as far as samples is concerned there are lots of free blog services with attractive templates available like wordpress, blogger, blogs, weebly, blogetery etc. all the very best for your blog