The most important advice for newbie is about security. Be careful because there are a lot of phishing attempts. Secure your coins in wallets and be extra careful with your passwords and private keys.
And remember to do your own research when deciding in what to invest.
As a newbie i think the best way for them to learn especially they want to participate in bounty campaigns is to read carefully bitcointalk threads because this is very knowledgeable if you take it seriously.