Starting a blog for profit is probably the easiest startup idea but requires quite some effort and consistency to be turned into a profitable startup.
Startup cost is next to nothing. All you need is a domain and a hosting account, and a blog can be put together using any of the available popular blogging scripts, like many other bloggers I would suggest wordpress but there are plenty of other blogging CMSs available online.
Finding the Right Niche
Getting this part right is crucial if you want to start a blog for profit. Every niche is a fair point of a percentile more saturated each new day and not every niche is as profitable as every other niche, since the idea here, is starting a blog for profit; you want to make sure that the niche you finally choose is not only profitable but also easy for you to write on. So get researching, go to places where people hang out, Facebook, Twitter, Yahoo Answers etc. See what's popular, observe the trends, find out if the niche is profitable or not, find out if there's a good competition among advertisers in this niche and if the consumers are willing to pay for information or product in this niche.
The trends and what kind of popularity and traffic you can expect in a particular niche can be learned by using the tools like Google Trends & AdWords Keywords Tool. Remember traffic is important when it comes to dual tray laser printer a blog for profit.
It goes without saying that the most important part of a blog is contents, so get writing, this is where most people starting a blog face a problem. For most people it is hard to come up with good quality fresh contents every day, for some it might be a breeze yet creating contents that can make your readers go WOW! is easier said than done.
An easier way for unlimited new contents is blog aggregation or auto blogging, as it is commonly referred to, the idea is to aggregate syndicated contents on your blog. The obvious downside, besides the fact that you won't be able to be prideful about the exclusive quality contents on your blog, is that all the contents that you will have on your blog will not be unique but simply copies of contents from other blogs, news websites, article directories etc, which in my personal opinion should not be a problem, as we are trying to build a blog for profit and not for fame.
The up side is that after not having to create any contents for your blog you will have all the spare time to drive more and more traffic to your blog, so as you might have figured it out by now that auto blogging is kind of fast track thing. Again, you cannot expect your auto-blog to become a benchmark in your niche but you can target several niche and build multiple moderately profitable blogs.