Fn + Backspace, Control + D
I'm assuming you are on a laptop without a traditional Delete key. If you are on a MacBook/Powerbook you would hold the Fn (function) key + Backspace to do a forward delete. You can also press Control + D to forward delete on any Mac keyboard (this method will only work in Cocoa applications, which are most applications released today with some notable exceptions such as Firefox).
If you have a desktop Apple keyboard, there is a Delete button above the arrow keys just like on a Windows keyboard.
You may also use something like DoubleCommand to remap any of the keys on your keyboard to whatever you wish.
Here are some more handy keyboard shortcuts you may be interested in as far as text processing goes:
These shortcuts can be used within all text areas in Cocoa applications.
option-left arrow move left one word
option-right arrow move right one word
option-up arrow move up one paragraph
option-down arrow move down one paragraph
control-left arrow move to start of current line
command-left arrow
control-right arrow move to end of current line
command-right arrow
shift + any of the above extend selection by appropriate amount
click then drag select text
double-click then drag select text, wrapping to word ends
triple-click then drag select text, wrapping to paragraph ends
shift-select text with mouse add to selection (contiguous)
command-select text with mouse add to selection (non-contiguous)
option-drag select rectangular area (non-contiguous)
command-option-drag add rectangular area to selection
drag selection move text
option-drag selection copy text
control-A move to start of current paragraph
control-B move left one character
control-D forwards delete
control-E move to end of current paragraph
control-F move right one character
control-H delete
control-K delete remainder of current paragraph
control-N move down one line
control-O insert new line after cursor
control-P move up one line
control-T transpose (swap) two surrounding character
control-V move to end, then left one character
control-Y paste text previously deleted with control-K
