Online Lead Generation is not that difficult but what you need to begin with is a solid sales and lead capture strategy.
This means you need to have a good offer and a good lead capture system in place.
Then, assuming these things are sound, you can use many different lead generation online techniques to attract targeted traffic and convert visitors to leads.
Techniques include things like Buzzoodle can help you with, such as inbound marketing and search engine optimization as well as things like Adwords, banner ads, commenting on blogs and many other ways to create targeted traffic. Trust my, the attraction is not as hard if you have built the proper lead conversion system in advance.