The Elder Scrolls V: Skyrim Glitches

Unlimited Steel Arrows
Go to Dragonsreach and get to the back 'balcony area' where Proventus Avenicci sometimes waits. There should be guards training in the area closer to the door back inside. If you happen to find one of these training guards with a Bow, just sit back and let them do their stuff. After a while, go and collect their arrows. They'll continue to train and shoot off arrows, and you can continue to collect them without penalty. This can be used for unlimited steel arrows, as the guard never runs out.