I'm SO sorry this took so long for me to do for you!

Okay, here's the deal - this is the most basic way to make a decent Bump map for 3D from a photograph.

1 - Make it Black&White by making a Hue/Saturation Adjustment Layer - click the little circle with F in it at the bottom of the Layers Palette - choose Hue/Saturation, move the Saturation Slider all the way to the Left to make it B&W.

2 - Shift+Ctrl+N (PC) or Shift+Cmd+N (Mac) to make a new Layer - change the Mode to Soft Light. Make sure it is in the middle in the Layer stack, below the Hue/Sat Layer.

3 - Get a Soft Brush, set to 100% opacity and flow, hit "d" to get the colors Default Black and White, and paint where directed. White for anywhere you want the bump to "rise" and black where you want the bump to "lower".

It is a good idea to save your progress at this point as a Photoshop Document - preserving all the layers so (if you want to) you can edit them further later.

Flatten the Layers (little right Arrow at the uper right corner of the Layer Palette - choose Flatten) and save as a TIF. Feel free to change the color space to Greyscale (Image>Mode>Greyscale) to lessen the file size. all color information will be discarded making it much smaller, and by saving it as a TIF (NOT a jpeg) it willnot be compressed and have artifacting at the edges which can make your bumps look funny.

Hope that helps - good luck and let me know if any of it is still unclear. Take care-
-Lew ;-)