When I'm stuck at a boss or a particularly challenging puzzle after contemplating it for a while.

Or when I didn't pay money and I'm just lazy.

http://www.nintendolife.com/forums/3ds/paper_mario_3ds

@Aviator I believe he was asking how frequently other people used guides in comparison to himself, not that he needed help. And no one has told him to go to Gamefaqs; I think he is perfectly capable of doing that.

Personally, I use walkthroughs a little more freely than others, mainly because I am afraid of missing items that can never be retrieved, etc.
And Majora's Mask; I just feel so lost in that game.

I used alot of walkthroughs towards the end of Pikmin because i couldn't kill Beady Long Legs, he would just kill all of my pikmin in my battalion.

Whenever I get really stuck on optional content. I've used them a few times with New Super Mario Bros star coins and other such collectibles, because frankly some of them would require a ridiculous amount of trial and error to discover otherwise.

Also, when the game is completely vague about some important gameplay mechanic that makes it nearly impossible to continue.

Is that sarcasm?

After approximately 15 minutes of cursing & swearing...

I look for help when it's game I really really like but I'm totally stuck and can't find a way to make progress. Like La-Mulana. It seems like it would have taken my entire life and dedication to beat this without guidance from the community. Looking for help in La-Mulana doesn't subtract from the experience that much for me personally, because the solutions to the puzzles are mindblowingly complex sometimes, and exceptionally hidden at other times. Maybe I just don't pay enough attention for the clues on the stone tablets. More often than not I really don't know what to make of these inscriptions. I've played plenty of games in the gerne, but this one is really teaching me new exciting stuff, so I'm rewarded even when having not solved everything on my own.

Before La-Mulana, at the start of the year, I checked for help on a similar WiiWare-metroidvania ROBOX I really liked. But there is no walkthrough, or FAQ, or maps, or even a community for it anywhere on the net. Like in Metroid in '86, I felt completely alone on that strange planet. So I've played it for many hours, exploring the lands again and again, then drawing my own maps, and luckily, eventually found all 100%. Very rewarding.

Maybe you have the desire to scan your maps and provide them on GameFAQs? I would totally appreciate it!!!

castlevania 2 on NES

At the first sign of trouble.

in game were im feeling like getting 100% or in older games that im just having trouble with.

When I'm stuck, usually. I also use it for hard games just so I don't have to spend hours in frustration.

I use them a lot, especially for Zelda games, because I increasingly have no shame about needing help and I'm no boasting completionist. When I want to finish a game to unlock hidden levels or whatever secrets that interest me, I'll use whatever resources I find and not fool around with punishing myself with a hard level in which I make no progress.

Either when I'm completely frustrated, when I feel the only way to 100% a game (on a second run-through) is to use a guide... or when I feel using a guide adds much more depth to a game.

A good example of the latter is Okami. I've played through that game, and felt I never really mastered it; I didn't know there were like a dozen hidden brush techniques, and keeping track of its insane amount of side-missions in its huge world is near impossible. I also felt like I never found an effective strategy against most bosses — unlike Zelda there is more than one way to tackle beasts. And like there should be more variety to the game than I've found so far. So I plan on playing through it again with a guide.

When you cant walk through something

After I've spent 30 minutes on something, then I will usually use that portion of the walkthrough and find out that the solution was obvious.

Same here. My most notorious moment was in the great deku tree in OOT. I didn't realize that you could burn the spider webs (or whatever they are)..

I only use guides/walkthroughs when I'm really stuck