@makinpaps - best place to start is to understand the different business models to see which one fits your style.
Most people start with Affiliate Marketing - promoting products on their own website, encouraging visitors to click through to a vendors website and then getting a commission for any sales subsequently made.
A variation of this which is popular is CPA Marketing or 'Cost Per Action' or 'Cost Per Acquisition' where you get paid for getting a visitor to take an action such as filling out an enquiry form for insurance. Theres a slight difference between the 2 definitions but they're pretty much the same thing.
Creating your own digital product is another very popular option and quite easy to do.
There's been 2 other models pushed a lot over recent years. Firstly, membership sites or continuity programs - basically getting people to sign up for providing them with ongoing information. And most recently, theres a lot of talk about 'offline marketing' where you can use your internet marketing skills to help local offline businesses who are not net-savvy.
Have a good look around Wickedfire for some great information, gooogle is your friend too
I'm sure that from your experience of trading, you'll already know the gap between hype and reality! So, go into this with your eyes open, find something simple that works and don't be fooled into thinking you'll make a million overnight. The secret is to TAKE ACTION; find what works, replicate it and scale it.
And finally, to answer your question about SEO and PPC:
SEO is Search Engine Optimization. This are the steps you take to make your web sites pages more visible to the search engines (google, msn, yahoo etc). This includes what you do on your site itself and also what you can do 'offsite' through techniques such as social bookmarking, article marketing etc
PPC or Pay-Per-Click is the specific advertising model where you create adverts which are displayed on search engines or on other websites and for which you only pay a small amount for every 'click' made on your advert. Be warned that this technique can cost you a lot of money if you're not careful so make sure you understand how to use it before diving in. That said, PPC can be an effective way to speed up your progress in internet marketing.
Hope all that helps and best of luck in your business ventures
Bentley