Placement/order of buttons

1. Where should I put buttons on my website?
2. Should next button be on left or right?

Where should I put buttons on my website?

Full page designs should have the primary button on the left side of the page. If the browser window is large, or you have to scroll down to fill out a form, it's best to have the primary button right below the last bit of content on the page.

Should next button be on left or right?

This also means that when elements are presented in a row, the most important items (e.g. the Next button) should be presented on the left. Left aligning the primary action will ensure that it comes first whether buttons are inline or stacked.