How to take pictures of your vintage bike 
Updated 9.29.2022

Approach:
We assume the purpose of taking these images is to tell the viewer as much as can be conveyed about this particular bike;
1.) It's cosmetic appearance, color(s), decals, chrome, pin striping, etc.
2.) How it was constructed by studying frame details, lugs, dropout junctures, etc.
3.) The specific components attached to the frame.
4.) It's physical condition

Preparing the bike for the "shoot".
1.)  Thorough but gentle cleaning (unless you desire the "patina" to be the subject of the pictures too.)
2.)  Consider using a "low luster" ArmorAll type product (silicon "protectant") on almost every surface.
3.)  Set bars, stem, saddle height & angle to a "normal" arrangement.
4.) Replace or treat elements showing excess wear or deterioration.

Choosing the setting for taking pictures:
1.) Outside in natural light is always best
   - Look for a light colored & minimally textured back ground.
   - Good options include a concrete wall, a solid painted wall.
   - Bad options are foliage, architectural complications, boulders & stones, highly textured surfaces, etc.
2.) Use available light & avoid direct light (bright sun is the least desirable) but with ample ambient light.
3.) Level ground, similarly uncomplicated or minimally textured.

Equipment needed:
1.) The assumption is that we are not creating a studio (that would be nice though!) but using what we can find, as described above.
2.) A "real" digital camera is preferred over a cell phone (although they get better every day!)
3.)  Use some sort of inconspicuous support for the bike. (might be able to just lean it/position it against the wall?)
4.)  Do not use the flash, but if possible, set your camera for low light use. A tripod will help! (Exception: a "fill flash" can sometimes work well but move relatively far away from bike to avoid glare.)

Shooting sequence:
1.) Try to shoot in a logical way, the way we look at bikes with our eyes when studying them. 
       This set of pics illustrates this technique as well.
      - First the overall look at the complete bike
      - then focus on the front end & all its details.
      - follow the down tube to crank
      - then  back to rear derailleur or hub
      - up to rear brake
      - on the seat stay "cluster", up to saddle
      - then along top tube back to handlebars.
      - Then there is the other side, same process!         
2.) Include carefully composed close-ups of those features which make up the bike's "personality" (lugs, dropouts, fork crown, special decals, seat "cluster.).

What to do with the pictures?
1.) Crop & edit the pictures for composition, light & dark, contrast & color saturation. There are many free programs, and one is possibly already included in your computer.
2.)  Save them in the largest format/resolution.
3.)  Use one of the online picture hosting services to store and refer people to them. Flickr is a huge favorite, and Google now has free hosting for gmail users. And there are others like Smugmug, Imgur,  Imageshack, and probably more.
4.) Include the bikes dimensions and key features in your picture album.