I think you got it right, except at the last sentence.  "Óláf vegr ormrinn."  not that our friend Olaf is in the accusative case (the object of the sentence), not the nominative case (Olaf + r, the subject of the sentence.), meaning that he is the one being killed, not the serpent. 

On Sun, Feb 6, 2011 at 2:00 PM, jeffery craft <warbuff_4@...> wrote:
 

.4 Translate the text into English
Óláfr heitir konungr. Hann á brand. Heitir brandrinn Tyrfingr. Úlf sér Óláfr ok segir: "Hér er úlfr!". Óláfr tekr brandinn ok vegr úlfinn. En hér er ok ormr. Óláfr sér hann eigi. 

olaf is called king.   he owns sword.  sword is called tyrfingr. olaf sees a wolf, also says: " here is a wolf!" olaf takes his sword also kills the wolf. but here is also serpent. olaf sees it not. olaf kills the serpent.
 
3.5 Translate the text into Old Norse
A king is called Sigurðr. He owns a sword but not a horse. Óláfr is also a king. He owns a horse. Sigurðr kills Óláfr and takes the horse.
siguror heitir konungr. hann a brandrinn en eigi hestr. olafr er ok konungr. hann a hestrinn . siguror vegr olafrinn ok tekr hestr.

is this right if not, please explain my mistakes and how to fix them
"Consider your origin, you were not born to live like brutes, but to follow virtue and knowledge.”
 
                                                                                                                                Dante Alighieri 
 
Ti. Aurelius Trio