I just got my first ebony sword, upgraded it to legendary, and now I want to put on an enchantment. The problem is that every time I disenchant an item and use that enchantment on something else the enchantment is much less powerful than it was originally. For instance, early in the game I had a magic resistance 15 percent on a cloak, but after disenchanting it and putting it on a ring it was only 8 percent. How do I make the enchantments stronger? Is that what the perks do? Sorry for the newb question.

Also, on an unrelated note, can you get max armor rating of 85 percent damage reduction through ebony armor alone?

P.S. I know I could google for this information, but I usually get other good advice alongside my question on the forum.

You've got to invest in perks in Enchanting.

What level is your enchanting. it seems like its about level 15 without perks.
you need to imrove your enchanting level and put perks in enchanting to increase the strength of your enchantments.
Pointless Edit: Enchantception.

All of the above. As your enchanting increases and the more perks you invest, that number will get much higher.

Your enchanting needs to be higher. Best results are to get all those 0/5 and straight up the middle.

Craft some Iron Daggers and enchant them, sell them for profit.

Enchantment strength is determined by Enchanting level, perks, soul size, and current active effects. Also, the enchantment will always display it's base value when you're looking at it, it gets immediatly modified when you select it (due to level, perks and active effects), and further modified when the soul gem is chosen. For highest results, use Grand Souls.

What's the highest power level of Enchanting you can achieve, without using glitches or mods?

Crafting and enchanting jewely and the most expensive armor/weapons you can craft or find. Enchantment like alchemy and smithing rewards you with more experience for the more valuable items though grinding stuff more basic will add to your total as well. And don't stint on that loot you find, stock up on filled soul gems and enchant all of that loot before you sell it, not only does it net more coin but keeps your enchanting skill rising. Same thing with smithing and heck use it as well before enchanting since improved equipment also raises the value. The more valuable when it's enchanted the better.

Damage reduction from armour is capped at 80%.

Yes, you can get there with ebony armour---but you will need either (i) the Ebony Smithing perk, or (ii) enchantments to improve your heavy armour skill. That's because at 100 Heavy Armour, with all the relevant perks, a full suit of ebony armour (not including shield) will give you 60% damage reduction.

However, without enchantments and without smithing perks, you can still get to about 72% damage reduction with ebony armour. Edit: I mean, you can get to 72% damage reduction by smithing the ebony armour without the ebony smithing perk.

Get your hands on some Grand/Black soul gems, the spell or enchantment of soul trap (or the Mace of Molag Bal with Azura's Star or The Black Star) and fill 'em all up by killing mammoths or humanoid targets. Also, bring a bunch of low level soul gems with to kill lesser creatures so you can recharge your magical weapons, as that will count towards leveling your enchanting skill. Though if you want a quicker and easier way, I have another way.