My previous game, I played as a relatively good character. This time I decided to play a thief. I'm running into a strange issue, though: I get a thieves guild job to rob a shop, but the owners seem to never ever go to sleep. The shop is the Pawned Prawn in Riften, and the doors seem to lock at about midnight or so. However, no matter what time it is that I try to break in, the woman of the house is either still standing at the counter or is cooking right at the entrance.

Same thing happened with the clothing shop in Solitude -- I'm supposed change the books, but one of the shopkeepers seems to ALWAYS be standing staring right at the shop entrance at all times of the night.

Is the only way to do this with invisibility? Or what?

I had the same problem. I don't think it can be done with invisibility either (the effect wears off as soon as you interact with the door to the inner room to get to the ledger). I gave up and and asked Delvin for another job. He moaned but there were no adverse consequences.

You should go in during the day. The shop keeper might follow you, but if you hide, they might think you're gone.

Yeah, some of them seem outright glitchy,

I broke into Belethors, finished my business, and the farmer (Pelagia) wanders in the backdoor and tells me I'm trespassing.

Maybe he saw you sneak in.

You can always go in during daytime. That way it is not trespassing, and if you can hide from the shopkeepers you can steal your goods. Another more desperate way is to just kill the couple in the Pawned Prawn, but I don't know if you want to play that bad. And of course you can always give up the quest, and get a new one from Delvin or Vex.

The whole sleeping thing in the game is ridiculous. I've seen kids running around at 2AM. Youn have to go in during the day and just wait. It's the only way to do it.

When I was a kid I didn't go to sleep until 4am. Then I slept all day.

I'm still a kid and I still do that.

go in during the day and drop into "sneak" when they're both upstairs... there's a lockbox on the thing at the end of their bed, you can get the dollar amount you need.

lots of shops and shopkeepers work this way, I have too low of sneak on one character who did this chain and can't drop into sneak in front of them... the other one can walk around behind them, sneak, pickpocket, take some things from the shelf and stand back up and they're oblivious. they really did design this game so that with enough "skill" you can do what you need to do even though the real you is a little freaky about being seen. just watch the eye on your screen and make sure you can reload back to the door if anything goes wrong.

note: I usually save on the OUTSIDE of the door, just in case

Also, if you're using the 'Wait' function to forward time a couple of hours in the hopes they go to sleep, do it in a different area. I noticed that if I wait right outside the shop (or house, or whatever) the people inside acted as if time hadn't passed; they were still in the same position. But, if I moved away from it to a different part of the town, waited there, and then went back to the shop, usually they'd gone to bed or at least moved around.

Put a bucket on their head, then you can do whatever you want! Haha, but, I noticed they dont sleep either, I tried feeding on them with my vampire, all that happened is they went "VAMPIRE!" and ran out, then I had to run from the entire town haha.

Changing the books anywhere is super easy. The owners don't have to be asleep or anything, just go in the daytime, sprint to the ledger (Not sure where it is in pawned prawn) drop into sneak, wait for the 'hidden' thing and press action button, done. I thought the thieves guild quests were a little too easy, there is no real sneaking or planning required. They could've at least made it so it takes some time to forge the numbers to have a slight chance of getting caught, but no Dragonborn is apparently either the fastest writer in Skyrim or business ledgers just change themselves when he's around cos they don't want to get shouted at.

Not young ones, under 13. Any parent that allows a child to stay up to 4am isn't doing their job. I should know. I'm a mother of a teenager.