I be Noob

That is a very broad question. Maybe the wikis can help:

http://www.uesp.net/wiki/Skyrim:Skyrim
http://www.uesp.net/wiki/Oblivion:Oblivion

Basically they are very similar in terms of an open world to explore, lots of dungeons and quests. They are set in the same fantasy universe so the lore is the same.

Some of the game play is a little different, like there are no perks or smithing in Oblivion, armor and weapons degrade when used in Oblivion, you can make spells, and many other small changes. The character creation is a little more complex. etc.

Is there anything in particular you'd like to know about.

Yea, thats a huge question with many different aspects to think about, OP! Its like asking the difference between United States and Canada.

oh....SPOILERS BELOW, btw.

From the top of my head...Things Oblivion has that Skyrim does not...and keep in mind these are just a few things...nowhere near to being a complete list. And keep in mind Im talking of the vanilla (unmodded) game.

You can mismatch curias and greaves in Oblivion; doesnt matter if theyre light and/or heavy armor. In Skyrim, these are one piece.

Skyrim has a very slow health auto-regeneration for all player characters AFAIK. Oblivion, I think its only a certain Starsign (forget which one) that auto-regens.

Oblivion has a more detailed facial/appearance system (when youre shaping and tweaking your characters face). There is more of a variety here.

Skyrim has beards for men, Oblivion has only 5 o clock shadows at best.

Oblivion is overall a much more hand-holdy game that tells you in greater detail what youre supposed to be doing next during quests. Im noticing Skyrim still does this, but isnt quite as in-your-face about it.

Oblivions countryside has more variety. Its more colorful. A lot of green, dedicious trees, vibrant meadows. Skyrim, in comparison, is more like a tundra environment. Lots more grays. The sun doesnt shine very often. When the sun does shine in Skyrim, though, it can be almost as vibrant as Cyrodiil.

..But Skyrim has Northern Lights at night sometimes!

Skyrim also has more non-threatening wildlife to appreciate and possibly hunt. Cyrodiil only has deer and some domestic animals like sheep.

As Savilian says, weapons and armor degrade in Oblivion, and youll have to keep them up by repairing them. Skyrim got rid of this (dangit) but Skyrim also added weapon, armor & jewelry crafting.

This is a biggie for some folks: Oblivion has spellmaking, Skyrim does not.

Oblivions leveling system is broken, a lot of folks say, because lots of things (creatures, NPCs, loot...etc.) level with the gamer. Skyrims leveling system is broken a lot of folks say, because we cant control it like we could Oblivion

Skyrim has a much greater draw distance than Oblivion. You can see enemies and friends and forts (etc.) from a greater distance, basically.

Skyrim has a grittier feel to it. Just an overall feeling that isnt as nice and pleasant as most of Cyrodiil. Both have spectacular scenery, though.

Oblivions dungeon areas tend to be more generic; (not my words, these are the words of others) because these dungeons tend to use a lot of cut n pastes. But the more Im dungeon diving in Skyrim, the more Im noticing Skyrim also has some cut and paste action...its just not as noticeable.
Oblivion has Oblivion gates during its Main Quest. Skyrim has dragons.

Oblivions NPCs are mostly simpleminded twerps who repeat the same stuff over and over during their random conversations. Skyrims NPCs are mostly simpleminded twerps who eventually repeat the same stuff over and over during random conversations, but at least Sky does a better job overall in this regard. A lot of the things Skyrims NPCs talk about arguably have more depth (my opinion) and you actually have to pay attention to what Skys NPCs say, because sometimes the most random side-talk can lead to quests.

Oblivion and Skyrim have different lockpicking systems. Oblivion is more like a mini-game, Skyrim is more intuitive. Kinda hard to explain. Its more like picking a real lock in Skyrim.

....ahh. thats all for now. As Savilian says, is there anything in particular youd like to know about?

I think one of the largest differences is that Oblivion has character classes, and Skyrim does not. You have to be very careful what skills you select as Majors in Oblivion, because they will determine how quickly you level. Often that means leveling too fast, and becoming weaker then the monsters. So in Oblivion, you basically need to know what skills your character is going to use when you create them, and which ones they will not. In Skyrim you can just start out with a blank slate, without really thinking about what kind of character you want to play.

I enjoyed Oblivion, but It's gameworld Is the worst out of the last three TES (The first two don't even have a gameworld so to speak).

Really? I hated that everyone has a baloon face in Oblivion... In Skyrim there are some race-related facial traits that you couldn't completely remove (that made the races more distinct), but I felt I had much more control over the look of my character.

That would be true if these random side-talks that lead to quests didn't add a quest entry into your "journal", even if you don't pay any attention to that NPC.

Actually, not all of them do. I've come across at least two cases of NPCs telling me about dungeons and Word Walls off-hand, without any kind of marker.

Totally disagree. Morrowind felt like a theme park with abrupt changes between wildly different environments. Oblivion had a much more realistic environment for a world of that size, while still including diversity in the form of arid highlands, lush swamps, open plains, snow-capped mountains, and everything in between. Cyrodiil is actually my favorite TES environment so far. Much of Skyrim is too dark and grey for my taste.

leveling is way different, and thier are these classes which some people make ass backward to effecent level (don't worry about it, its not as important as people say)

magic has its own button, and there is no dual wielding, also no shouts.

Staminia is even less important

Differences between Skyrim and Oblivion

1. You had better learn Oblivion's leveling system and level efficiently, or you will be very sorry when the world becomes stronger while you remained weak
2. Skyrim has dragons, Oblivion has Oblivion gates
3. Spellmaking
4. The IC Arena
5. Oblivion main quest and guild quests are longer
6. Skyrim lets you chose between Legion and inbred stormclowns. Oblivion gives you no choice but to help the Blades
7. The Blades are not the kooks that they are in Skyrim
8. Archery is weak and Magicka is strong for Oblivion. Reverse for Skyrim

All i can say is that it's much simpler.

Leveling is the same. Except you have your Major and Minor. In Skyrim you don't.
Enchanting is very, very different and it's slower to increase. Not even that, but to gain access to an Enchant Table you would need to join the smelly Mages Guild. Unless if you have plug-in.

As for loot many of the things are worth [0] for gold. So looting a cave is pretty much useless and won't get you that much money, also not much compared to Skyrim and Morrowind. Which had a variety of things.

Skyrim alone is jammed packed with things to do and sell. Now imagine once DLC hits !! .

I think Renee is talking about the sliders themselves. Oblivion allowed much more in the way of fine-tuning facial features ( two hundred settings per slider, as opposed to Skyrim's ten to twenty).

I think the miscommunication here is that Renee is talking about the process. You're talking about the result.