The New universe was essentially what it was entitled..lol.. a "new" Marvel comic book Universe..it was started in the mid 80's by Marvel in an attempt to branch out from their standard "comic book" universe and have more realistic storylines...some of the titles of the line were DP7..Starbrand..and their were a few others..it tanked pretty bad...Starbrand was the only title that had a descent fan following..
As for what the starbrand is and what it does..well..its kind of like the Infinity Gauntlet of the NU(New Universe) and the wielder of it can essentially do anything they want..since its power has been stated to be infinite.
I believe that it only gives the wielder omnipotence..and not omniscience(just my opinion)...most of the users however..just use the brand to become a "superman" of a sort
...people who have possessed the brand..always retain a fraction of its powers after transferring it to another wielder..and can not die..
Quasar go the brand when he was inadvertently sent the NU while traveling across the multiverse to help out Utau the Watcher...and got blasted out of Marvel's multivers into the "Omniverse"(series of multiverse's..which would include DC, Image, Dark horse, and the real world multiverses..) He received the brand from the NU's original wielder, and had to use the brand to get himself back to Marvel's mainstream multiverse..