I want to get an ebony helmet from somewhere, and I don't have a high enough smithing to make one. Where is the best place I can find one?
Boss chests at the end of a dungeon are your best bet, since those things are random. Keep in mind that ebony armor will only start showing up after you reach level 32, and even then not frequently.
At higher levels, mercenaries (a random encounter) will have a chance to be equipped in ebony, apart from those ebony armor is very rare.
If you have the Dragonborn DLC installed:
Upon reaching level 80, a mysterious warrior wearing a full suit of ebony armor will approach you in any major city, such as Whiterun, and challenge you to a duel at his "last vigil".
He will always be equipped with the following items: Ebony Armor of Regeneration, Ebony Boots of Frost Suppression, Ebony Gauntlets of Extreme Wielding, and an Ebony Helmet of Waterbreathing, as well as a Necklace of Shock Suppression and a Ring of Peerless Wielding.
...once you have defeated the Ebony Warrior, the quest will conclude and you may loot his body for his fully enchanted set of equipment.
I find ebony in almost every chest at the end of a dungion and I'm level 38, also if you have it and your conjuration is level 90 or above talk to Phinis Gester at the college of Winterhold (after joining the college). Then ask if there's anything else I can learn about conjuration. He will then gives you a really short quest and you get a sigil stone you can place at the atronach forge. Next, make deadric items by having the ebony item you want to turn into the same type of deadric item (except you can't get deadric boots for some reason), a black soul gem, a dwarven centurion core, and a deadra heart. After that you put that in the offering box and pull the handle (if your conjuration isn't 90 buy soul trap from the same guy and keep casting it on a dead animal). I was level 56 an it took me like 15 minutes but it does work.