Keyboard Commands
There are many keyboard shortcuts that the informed commander can use to maximise their time most effectively. The majority of these keys are scattered throughout Cavedog's literature. A few I have even found myself :P

TA Game Keys Prefix Keys TA Demo Recorder Keys (some user defined)

Game Keyboard Shortcuts
A
Attack
B
Build
C
Capture
D
D-gun
E
Reclaim
F
Toggles fire orders
G
Guard
H
Share Resources (Multiplayer only)
K
Cloak
L
Load Unit
M
Move
N
Center screen to next unit off screen
O
Orders
P
Patrol
R
Repair
S
Stop
T
Track unit (toggles between units when more than 1 is selected)
U
Unload Unit
V
Toggles move orders
X
Toggles unit off/on
1-9
Select squad (Requires +switchalt, else ALT+1-9)
ALT+1-9
Select unit build menu page (Requires +switchalt, else 1-9)
+
Speed up the game (max +10)
-
Slow down the game (min -10)
~ ! # *
Show unit health (Toggle)
, <
Select the previous menu for that unit
. >
Select the next menu for that unit
SHIFT
Hold down to queue up multiple commands
ESC
Cancels the current command before it is executed
TAB
Multiplayer options
* Options - Options menu (F2)
* Allies - Make and break allegiances with other players
* Share - Share resources, map info and units with other players
* Control - Available only to the game creator, used to reject players from the game
SPACE
Show how many units you have
PAUSE
Pause (Doh!)
ENTER
Command entry and Multiplayer chat
* Allied chat precursors - a; a: a, (E.g. A: you OK?)
* Enemies chat precursors - e; e: e, (E.g. E; you r soooo dead!)
* Specific player (player #) - #; #: #, (E.g. 3; I'm dead man lemmie alone!)
* Hide command from enemies - 'allies' suffix (E.g. +shareradar allies)
F1
Unit Info (place cursor over unit of interest)
F2
Options menu
F3
Go to unit that last reported to you
F4
Toggles scorecard tallying the kills and losses for each player
F5-F8
Jump to map bookmark (CTRL+F5-F8 - Creates a map bookmark)
F10
Switch modes (normal to debug)
CTRL+F10
Movie Mode - Toggle on/off frames of movie recording (30fps default). Also used with +filmspeed #, where # sets the frame rate
F12
Clears the screen of messages
ALT+F4
Exit TA
CTRL+A
Selects all units, including the Commander
CTRL+B
Select all construction units except the Commander. If you have the TA Demo Recorder this will move you to idle construction units (very handy!)
CTRL+C
Centres the screen on the Commander and selects him
CTRL+D
Self-destruct the selected units. Press again to cancel
CTRL+F
Selects all factories
CTRL+M
Multiplayer chat (Same as ENTER)
CTRL+P
Select all aircraft with weapons AND CORE Thud k-bot! (damn bugs)
CTRL+R
Select all radar, radar jammers, sonar and sonar jammers
CTRL+S
Selects everything on the screen
CTRL+V
Select all aircraft
CTRL+W
Select all mobile units with weapons except Commander
CTRL+Z
Select all units of the currently selected type
CTRL+1-9
Creates a squad
CTRL+F5-F8
Creates a map bookmark
CTRL+F9
Take screen shot
CTRL+[
Remove all text in message box

Battle-Room Keyboard Shortcuts
TAB
Exit chat window. Repeat for options
M
Metal. Arrows keys to adjust
E
Energy. Arrows keys to adjust
D
Dead Commander. 'D' to toggle
L
Location. 'L' to toggle
I
Mapping Mode. 'I' to toggle
N
Line of Sight. 'N' to toggle
C
Cheat Codes. 'C' to toggle
W
Watching. 'W' to toggle
G
Game status. 'G' to toggle
A
Max Units. Arrows keys to adjust
B
Build Restrictions
* L - Load List
* S - Save List
* R - Reset List
* O - OK
* C - Cancel
S
Select Map. Arrows keys to scroll
* S - Select Map
* C - Cancel
R
Start Game