(Warning noobish question ahead). I'm building an N64 portable and am almost done but don't know how to put on a DPDT switch. Mine has 6 pins (2 rows of 3) on the bottom and I'm not sure where I solder them on and witch pins to use. Any info wouild help.

So I suppose you're putting the dpdt switch in for the 3.3V and 12V lines.
---(3.3)
---V V
|=X=X=X=|
|======-|
|=X=X=X=|
---/\ /\
---(12)
It's a horrible picture, but it kinda shows how it is.

Thanks I get what the picture means but do i also need a toggle switch?

No, the dpdt should be fine.
Also, you could use a spst and just use it to turn off the 12v line depending on if you're using a 3.3V regulator or a seperate pack for the 3.3V