First you need to decide what you want your blog to be about. What are your interests? Since you are going to be spending a lot of time working on it, it should be something you are passionate about. Anything at all.
Second, sign up at http://www.blogspot.com or http://www.wordpress.com .
You will need to decide your blog name carefully. Make sure it reflects what your blog is about.
There are basically two ways to make money from your blog. The first way is to monetize your blog. Both Blogspot and WordPress give you the option of doing this. Basically, from your account you will accept google ads onto your blog. You will get paid for impressions, but mostly for click throughs.
As far as designing your blog, both Blogspot and WordPress have tutorials to guide you in designing your blog. You’ll learn a lot just by trial and error too.
The second way to make money on your site would be from referral links. You should sign up for http://www.linshare.com and http://www.cj.com These are affiliate centers where you can partner with online businesses. When you put your special affiliate link onto your site and people click through and make a purchase, you get a commission. The best way to utilize affiliate links is to include them in your posts naturally, as people will be a lot more likely to check them out with a personal recommendation from you.
Now you’re all set up, but you need a following. No problem. The first thing you should do is include your blog link as a signature to your email. Then go to your favorite group site.. yahoo groups, google groups, etc. and search for people interested in your blog topic. Since you chose something you are passionate about it will be a pleasure for you to talk about it anyway so join a lot of groups. Don’t just advertise though. Really contribute to the conversations and be helpful. And always include your blog address in your signature.
You can also find forums on websites dealing with your subject matter that you can join in with.
Another way to promote your blog is to write articles to submit to http://www.ezinearticles.com and websites like it. Basically, you write articles that people with ezines pick up and use for free, but your byline travels around which gains you free advertising. It’s a win-win situation.
Once you start making enough money, you may want to advertise on Google Ads yourself, or maybe put an ad on Facebook.
Don’t give up. If you work on your goals every day, you will make some progress. Just like anything else it will take time. It is great to work from home, but it is still work. All the best to you in your endeavor!