I have to pick pocket a guy in Markarth, but even with 2 pieces of jewelry that each add 40% pick pocketing, the item I need to steal is 0% chance. Is this a glitch?

I doubt it. Pickpocketing is hard at lower skill levels and I think it's even more difficult for the Fishing Jobs. I'm assuming that's what you're doing since you "have to" pickpocket him.

So I need to do some series leveling of this skill before this quest will be possible?

I think it's glitched. I have a ring and a necklace that add 40% each, then I have my thieves guild boots on that add 15%, the item I need to pick pocket is still at 0%. I am only level 27 pick pocketing, but I can't imagine that that would keep it so low.

I don't think it is glitched, it is heavily reliant on skill level. Some advice for leveling pickpocket is to get training in a skill, save, and attempt pickpocket the gold back until you succeed. With high amounts of gold this will level pickpocketing a lot and make it much easier doing fishing jobs.

I think it's glitched. I have a ring and a necklace that add 40% each, then I have my thieves guild boots on that add 15%, the item I need to pick pocket is still at 0%. I am only level 27 pick pocketing, but I can't imagine that that would keep it so low.

This will seem counter-intuitive: but try removing one of the 40% bonuses and see if it helps.

I did. It didn't. Thank you for all the help. I actually decided to delete all game files and reinstall the game. I've been having TONS of issues and this is the last thing I can think of that may help all the freezing and crashing issues

If it's displaying a 0% chance, I'd think there is some glitch involved.

I have heard of a supposed "wrap-around" bug, where if you have enchantments or potions that boost your Pickpocket skill over 100, it wraps around back to zero. I don't know if that's a real thing, but it might be worth checking out. Unequip your pickpocket-boosting gear and see if your chances improve.

It could be a glitch then, but, be advised: it's more difficult for the Fishing Jobs - I had a hell of a time when I started them, but it leveled quickly. Also, I've heard about the "wrap-around" bug as well.

Some of the +Pickpocket% enchants are known to be glitchy, so it's better to just level up the skill. Even at 100 Pickpocket with most of the relevant perks, some items still show less than 90% probability for me and I still see a few 0% from time to time. Still, I remember my first Fishing Job at 30 Pickpocket was to take a Gold Diamond Necklace from Grelka in Riften. 0% chance no matter what I did so I abandoned the quest. Even at my current level, expensive jewelry like that or a large amount of gold or heavy items still give me a VERY low success rate. Like 20%ish.