Someone I know has been into photography and has recently expressed interest in freelancing.

There are a lot of questions she has, but the most pressing one is how to get paid. I have advised her to not charge too low as her pictures are good (and I don't want her to diminish the value of local photogs).

The problem is how to accept payments and what are some gotcha legalities.

What about cash? Should she provide some sort of "invoice" to customers so there is a proper record? How about checks? She plans on using her name, so I don't think she needs a DBA (doing business as) but I may be mistaken, to operate so how would one make a check to her?

PayPal seems interesting too but would she need a separate "business" account? I've browsed photo.SE for the last few hours but didn't find anything specific to accepting payment.