Bruce K. wrote:
I'm trying to attach an unfinished headboard to a bed frame.

This requires me to drill 4 holes into the wood to mount the headboard
to the bed frame.

Is there any cheap guide or tool that will let me drill these holes
with a portable drill?

Thanks in advance for your help.

Bruce

I can't see your headboard, but are you sure you need to drill exact 90
degree angles? If you are just drilling through, say, 3/4" wood to put
screws or bolts into the bed frame, you shouldn't need to do much of
anything special.

If you really need to drill accurate 90s with something inexpensive,
you can get drill attachments such as this:

http://tinyurl.com/9w452

Ken