lets skip the pleasantries and get to the important stuff. olaf, like any other nordic mage, should be in the mid lane where he belongs. lets talk about olaf's purpose on your team. his job is to charge in first, due to his tanky items (doran's ring, sorcerer's shoes, etc). if you know you cant win the team fight, you and your team MUST kill yourselves on their towers and try again next time. eventually you will win. remember this, and all will go well.

first off, we'll start with a properly handled scenario. i am playing olaf at mid, their jungler is lee sin. i push the tower at half health while the bot and top lanes are mia, all while ignoring the pings in the river. i am killed. why did i ignore the mia and pings? it confuses the enemy, causing you to win. 1 death (albeit 27 total) is not much, considering how nooby your team will surely be. after that happens, proceed to start jungling. grab blue buff and go to the stone bros. then you're done. if the enemy team has not surrendered in total shock, disconnect immediately.

IN CONCLUSION... this is the best guide out there for olaf. have fun!