not sure where you are starting from however it seems from your suggestions that your coming from the south east. easiest way in is a2 over black heath, depford, new cross past the sainsbutys on the right and bare left at the bottom just past the bus depot onto the queens road then turn right at camberwell green onto denmark hill follow your nose up past the maudsley etc then turn right onto milkwood.
if you cant get along the queens road you can go to the elephant and castle and turn down walworth/camberwell rd.
if you need the other end of milkwood be warned you cant turn right from denmark hill rd onto cold harbour lane. to turn onto cold harbour lne you have to take the left before hand and follow the road round but i warn you there is a morrisons there and the muppets parking make make it very tight not to mention the delivery vans dumped.