Don't get sucked into scams like "Make $10,000 in 30 days" because you won't and it will cost you money.
It is a real possibility to make money online and I am doing it now, but it takes time and it is not easy. It is certainly not a get rich quick scheme. If you have little or no money you really only have two choices. You can create a blog which is free and there are millions of them out there, so you have to look for a small market that no-one is currently providing information to. That is quite difficult to find.
The other option is a website and you can get some for free but you won't get your own specific domain name.
You can actually build and host a website for around $50 a year so that's an option. Then you need to get traffic to the website which is hard but here are some tips for doing that.
Getting traffic to your website is the hardest part and paid adverts is an expensive way of doing that. Here are some free resources that worked for me.
Write articles about your subject and post them to article websites, there are about 10 of those and you are allowed to reference your website in them. Just google articles and you will find them.
Look for forums on your subject and participate in them as that is where you will find people interested in your chosen subject.
Also use social networking sites to share your information.
These are all free and worked for me.