less

# Go to end of file:
G

# Go to start of file:
g

# To edit the current file in $EDITOR:
v

# Search in file:
/<searchterm>

# Next result:
n

# Previous result:
N

# Toggle search highlighting:
Alt-u

# Follow (tail -f) a file after opening it:
F
# To start less in follow-mode:
less +F <filename>

# To disable the terminal refresh when exiting:
less -X

# Move to next file (if multiple files opened, eg. `less file1 file2`):
:n

# Move to previous file:
:p

# Don't wrap long lines:
less -S <filename>
# or if already in less:
-S

# To save the contents to a file:
# Method 1 - Only works when the input is a pipe
s <filename>

# Method 2 - This should work whether input is a pipe or an ordinary file:
Type g or < (g or less-than) | $ (pipe then dollar) then cat > <filename> and Enter.