To resize and save your layout for sharing on the web or emailing,
it's an easy matter using just one dialog box.
Go to File>Save for Web. In the lower right corner, click
the Image Size tab and type in the new size: between 500 or
600 pixels in Height. Click Apply. The Width will stay in proportion
if the Constrain Proportions box is checked.

Next, choose JPEG from the drop down box under Preset, and
then choose a quality from the box just below it. In the Quality
slider, fine tune the quality as needed to keep the file size
under 125kb for uploading to DSP.
Click the 2-up or 4-up tab above the image preview to see the
image preview at various quality levels. Under each preview
is the size the file will be. Choose one of these previews that
is under 125kb with an acceptable quality, then click Save.
The quality will vary for each image depending on how many colors
is in it. Monochrome images save well at low quality, but colorful
images need higher quality. If the quality is very grainy, try
using smaller image size dimensions.
If desired, before clicking Save, preview the image on the
web to make sure it has good image dimension sizes and quality.
Click the Preview in Default Browser icon at the bottom of the
screen.
After choosing Save, name the file. It's a good idea to create
a new folder for web size layouts in JPG format, and give them
the same name as the original PSD file.
If desired, first go to Layers >Flatten Image, but it's
almost never necessary. Sometimes some effects may be distorted
when saving for the web, so occasionally when this happens you
can Cancel the save, then Flatten all the layers before saving.
After resizing and saving the file, it's time to upload to
the web. Go to this link
for instructions on uploading to the DSP gallery, and congratulations
for sharing your work!
For a printable version of this tutorial, click
here