Question: When asking an "ID My Bike" question what information about the bike should I include? 

Would a good "ID My Bike" question need all of the following or are there a few key things that would offer the best chance of an ID? Maybe something like - if these three things are included the chance of ID is 50/50. If these two things are added to that the chance goes up to 80%

**Pictures** (maybe some coaching on how to take good pictures) 

* every major frame joint
* all decals/logos/stamped names
* every component
* Other

**Words**

* Serial number
* Information about my current knowledge of the bike
* Links to information I have found so far
* Other

Answer: 
In order to ID a bike a question **must have**:

At least one clear picture.  

If there is no picture there is zero chance of providing an ID. The question will be closed.

The picture should be high resolution (any modern smart-phone will work)

In the picture the bike should be:  

 - well lit
 - right side up (sitting on it's wheels)  

 - of the whole bike  

 - from the chain side of the bike flat on. 

Pictures of the following are helpful:  

 - head badge ( on the front of the frame)  

 - logos  

 - decals  

 - distinctive frame features (lug work, square tubing, etc.) 

Other helpful information:  

 - Country in which the bike is located.  

 - What has already learned or is known about the bike.

Here is an example of a good picture.  

[![Required and Optional Pictures](https://i.stack.imgur.com/pXhFv.png)](https://i.stack.imgur.com/pXhFv.png)

This answer is a summary of the excellent answers provided by Argenti Apparatus and Criggie
First, accept that the chances of your bike manufacturer, brand or model being identified are low, effectively zero in many cases (repainted BMX frames, generic 80's drop bar ten-speeds, 90's inexpensive hybrids ...)

Having seen a great many id-my-bike questions on this site I think the goal is not so much getting the bike identified but avoiding looking like an idiot, collecting sarcastic comments and getting your question closed as a duplicate of [Why shouldn't I care what model/make/year my bicycle is?](https://bicycles.stackexchange.com/questions/52060/why-shouldnt-i-care-what-model-make-year-my-bicycle-is) within 20 minutes. 

That said ...

An absolute necessity is well lit, high resolution, straight-on photo of the whole bike, right way up, from the drive side, with an uncluttered background.

Include the year of sale when new if you know it (or a guess). 

Description or photos of major groupset components helps. Knowing the series/level of derailleurs, crank, shifters, wheels etc. can help narrow down the year range and model level.

Any other info or photos you can provide won't hurt, but don't raise the probability of an identification much it seems.

A piece of info that is generally left out that I think might help in some cases is the country or location where the bike is.

Including the serial number generally won't help. Collectors have made databases of numbers of a few collectable brands, and sometimes someone will be able to decode a numbering scheme, but in general they are meaningless as manufacturers don't provide a serial number lookup that will provide model or component configuration to the public.