The reason that I say this is that it does not cost you a lot of money to get started.
You can use free platforms like Blogger or Wordpress to get going.
I suggest that you go for the Wordpress platform if you are serious about making a business out of your blog.
However, you will most likely require somebody on the technical side to assist you as it requires technical skills to set up and also uses a MYSQL database.
I also suggest that you get your own web hosting so that you are not restricted to what you can do.
Also if you do not do this later on you will lose all your search engine rankings when you migrate to your own web host.
The most important part is to choose an idea that you will enjoy.
This is important because you will be working with this for a very long time.
So for example if you enjoy golf I suggest that you create a blog that teaches how to have a super effective swing.
The biggest problem that you will face is to get sufficient traffic to your site.
Since traffic is the life blood of your internet business it is a skill that you need to master.
The easiest way to get this is to submit all your quality posts to blog carnivals.
These get a lot of traffic and you will benefit enormously from this.
Also submit these posts to web 2 sites like Digg and Netscape and if they become popular you will benefit from thousands of visitors to your site.
You can monetize your sites by reviewing affiliate products that are related to your market.
If people are interested and you have written a favourable review then there is a very good chance that they will purchase the product.
Apply this formula to many different niche markets and you will build a stable internet business.