- Nielsen
"Label buttons with what they do." - UX Matters
"If you make a button too big, it may no longer look buttony" - UX Matters
"Best place for a button?: aligned with left-hand end of text-boxes" - Slide 36 - Jannet. Usability consultant
Place Important Content on the Left of a Web Page - "People brought up in cultures where language is read and written from left to right have been trained early on in life to begin at the left of a page, whether in writing or reading a book. This can be the reason why many web users spend a majority of their attention on the left side of a web page — as much as 69% of the time" - Six Revisions
Left or right aligned seems to be more common - Smashing Magazine 'Modern forms' article