Welcome to HubPages!
There are many affiliate programs online that one can promote to earn money online. Before I go there, let us look at Hub Pages. Writing on HubPages gives you the opportunity to earn money from HubPages own Ad Program, eBay, Amazon and Google Adsense. You can also earn certain percentage of your referrals income, provided they become hubbers within 30 days of signing up.
HubPages only pays through PayPal. From PNG, you can only send money through PayPal but not receive - check PayPal website for more info. Google Adsense and Amazon pays through cheque internationally once your earnings reaches their payout threshold. EBay earning is added to HP Ad Program earning and paid through PayPal.
Back to your question, it's broad but these are the basics for internet marketing, where you want to promote affiliate programs on your website, blog or through your articles/hubs and make money.
1. Check the program if residents from PNG can participate in.
2. Check the method of payment for your earning to see if you can be paid.
3. Sign up for the affiliate program, most are free. You will then be given an affiliate link. This is the tracking code that will be used to pay you commission when you refer sales through your affiliate link.
4. You can sign up through the merchant directly or you can join one of the Affiliate Networks such as Commission Junction, ShareASale, etc, and get a link through them. Commission Junction and ShareASale pay internationally through your preferred method of payment.
5. If the digital products are sold through ClickBank, online digital marketplace, note that PNG is not an approved country.
There are thousands of affiliate programs online. Just beware of internet scams.
If someone tell you you've got to pay so much to join an affiliate program, beware. If you are told that you will earn so much, doing very little work, beware.
I hope this helps. There are many resources on internet marketing you can find online. I wish you all the best.
If you need further assistance, message me on FaceBook. I will try my best to assist, if I can.