Virtualize Firefox using something like...
- Dell Secure Browser
- Sandboxie
- Defense Wall
- ThinApp
after you have virtualized Firefox you should start using Lastpass to manage your passwords and install NoScript and AdBlock add-ons. Disable notifications for NoScript and enable scripting on trusted sites only.
Virtualizing your Browser will stop malware from infecting your system but it still will be able to run inside the sandbox so you should reset the sandbox if you think you are infected from a website. The Dell Secure Browser is pretty easy to reset.
LastPass will fill passwords for you on the site that you save them for so you don't have to worry about keyloggers and there is less worry of giving your information to malicious people. They would have to poison your DNS to make LastPass see the correct URL.
AdBlock will stop most advertisements which slow down the loading of websites and can carry malware.
NoScript can be very hard to get use to because almost all websites are broken until you enable scripting for them but it is a huge safeguard. You should try to use it and when visiting a website click the S symbol in the bottom right and allow scripts for the website you visiting if you need to. You may need to enable more than one URL e.g. YouTube you need to enable youtube.com and ytimg.com so that you can view videos.