How do you get glass armor oblivian elder scrolls iv?

Glass armour is the best light armour in oblivion (not counting dlc or expansions). It should hopefully start appearing in shops to buy when you get to level 19 or 20. It will be worn by bandits etc slightly earlier than that. You will find that virtually no bandits wear full sets of armour. They usually mix pieces from different sets. So you will hve to go through a few bandits to get the full set. In quests, some important enemies such as named bandits or marauders will wear a full set of armour. The only certain piece of info i can give is that you will have to look for a while to get the whole set. One piece always seems to elude you. For me it took about 6 real life hours to find a dwarven helmet seeing as i didn't want to buy one. but anyway, good luck!