I found a good site of quotes. I pulled out some of the ones I particularly liked. But you can see the full list here:
World of Inspiration – Inspiration, Motivation, Inspirational & Motivational Quotes / Quotations
“Success seems to be largely a matter of hanging on after others have let go.”
William Feather
“Far better it is to dare mighty things to win glorious triumphs, even though checkered with failure, than to take rank with those poor spirits who neither enjoy much nor suffer much, because they live in the gray twilight that know not victory or defeat.”
Theodore Roosevelt
“Only those who dare to fail greatly can ever achieve greatly.”
Robert Francis Kennedy
“Losers visualize the penalties of failure. Winners visualize the rewards of success.”
Rob Gilbert
“There are no great people in this world, only great challenges which ordinary people rise to meet.”
William Frederick Halsy, Jr.
“Men succeed when they realize that their failures are the preparation for their victories.”
Ralph Waldo Emerson
“The individual activity of one man with backbone will do more than a thousand men with a mere wishbone.”
William Boetcker
“There isn’t a person anywhere that isn’t capable of doing more than he thinks he can.”
Henry Ford
“How many a man has thrown up his hands at a time when a little more effort, a little more patience would have achieved success?”
Elbert Hubbard
“Success, real success, in any endeavor demands more from an individual than most people are willing to offer?not more than they are capable of offering.”
James Roche