Which unique light armors are added by OOO and any hints as to where to find them (general tips, leave some exploring to me ^^)? And what about bows?
This has been probably asked millions of times but what are good dungeons to explore on lower levels(2-7)?
There's a set of Blue Glass armor spread throughout Cyrodiil. Hard to give general tips on finding the pieces, though - keep your eyes peeled while dungeon crawling. The Drakefired set isn't unique, but there are very few pieces of it. Also glass and also hard to give general tips on finding the pieces.
The Winged Bow looks cool (part of the Pegasus/Winged set) and is on par with Daedric IIRC. You'll come near it when doing the Skyrim Bandits questline. Also, the Meteoric Iron bows are nice - handplaced around Cyrodiil as the rest of the set.
Focus on bandit and Goblin dungeons on the first couple of levels. Also, the further away from civilization the harder it gets generally - so stick close to towns in the beginning (there are some notable exceptions to the general rule that dungeons close to towns are easiest, though...). But it's fun to push it on lower levels as well - plus it pays off. Nagastani, between Imp City and Cheydinhal, is one of my favorite dungeons to try on low levels, for example. Think I've done it on Lvl 3.
Also, check out http://www.gamesas.com/index.php?/topic/1088301-beginners-tips-for-ooo/.