Here is an alphabetized list of Publisher's most useful commands, followed by their corresponding keyboard shortcut:
Add a non-breaking hyphen -- CTRL+SHIFT+-
Add a non-breaking space -- CTRL+SHIFT+SPACEBAR
Add a page after the current page -- CTRL+SHIFT+N
Add a shadow -- CTRL+D
Add or remove hyphens -- CTRL+SHIFT+H
Align left -- CTRL+L
Align right -- CTRL+R
Bring to front -- F6
Cancel selection of a text frame or table -- ESC
Center a paragraph -- CTRL+E
Change text font -- CTRL+SHIFT+F
Change text size -- CTRL+SHIFT+P
Change text style -- CTRL+SHIFT+S
Check spelling -- F7
Copy formatting -- CTRL+SHIFT+C
Copy selected text or objects -- CTRL+C
Create a new publication -- CTRL+N
Cut selected text or objects -- CTRL+X
Decrease font size by 1 point -- CTRL+[
Decrease kerning -- CTRL+SHIFT+[
Delete a text frame or table containing text -- CTRL+SHIFT+X
Delete the next word -- CTRL+DELETE
Delete the previous word -- CTRL+BACKSPACE
Double-space lines -- CTRL+2
Find -- CTRL+F
Find and replace -- CTRL+H
Group or ungroup objects -- CTRL+SHIFT+G
Hide or show special characters -- CTRL+SHIFT+Y
Highlight all text in text box or table cell -- CTRL+A
Highlight one character to the left -- SHIFT+LEFT ARROW
Highlight one character to the right -- SHIFT+RIGHT ARROW
Highlight next page in page navigation control -- SHIFT+F5
Highlight to end of a line -- SHIFT+END
Highlight to end of a paragraph -- CTRL+SHIFT+DOWN ARROW
Highlight to end of a word -- CTRL+SHIFT+RIGHT ARROW
Highlight to start of a line -- SHIFT+HOME
Highlight to start of a paragraph -- CTRL+SHIFT+UP ARROW
Highlight to start of a word -- CTRL+SHIFT+LEFT ARROW
Increase font size by 1 point -- CTRL+]
Increase kerning -- CTRL+SHIFT+]
Insert a frame break -- CTRL+ENTER
Insert a tab in a table cell -- CTRL+TAB
Italicize text -- CTRL+I
Justify text -- CTRL+J
Make text bold -- CTRL+B
Make text small capitals -- CTRL+SHIFT+K
Make transparent or opaque -- CTRL+T
Move between background and foreground page -- CTRL+M
Move between current page view and actual size view -- F9
Move between menu bar and publication -- ALT
Nudge down -- ALT+DOWN ARROW
Nudge left -- ALT+LEFT ARROW
Nudge right -- ALT+RIGHT ARROW
Nudge up -- ALT+UP ARROW
Open current publication -- CTRL+O (letter O)
Paste text or objects -- CTRL+P
Print -- CTRL+P
Redo previous action -- CTRL+Y
Remove line spacing before a paragraph -- CTRL+0 (zero)
Resize object, keeping its center -- Press and hold CTRL and drag a Resize handle
Return character formatting to current text style -- CTRL+SPACEBAR
Rotate object freely -- Press and hold ALT and drag a Resize handle
Rotate object in 15-degree increments --Press and hold CTRL+ALT and drag a Resize handle
Rotate object five degrees clockwise -- CTRL+ALT+RIGHT ARROW
Rotate object five degrees counterclockwise -- CTRL+ALT+LEFT ARROW
Save changes to a publication -- CTRL+S
Show or hide boundaries and guides -- CTRL+SHIFT+O (letter O)
Single-space lines -- CTRL+1
Soft return -- SHIFT+ENTER
Turn on or off the Snap to Guides feature -- CTRL+W
Underline text -- CTRL+U
Undo -- CTRL+Z (up to 20 actions)
For more on getting the most out of your Publisher program, also check out DTP channel writer Carolyn Taraboletti's similarly titled piece.