Hiya
good
and free might be pushing it! And if you are looking for advice in English then...anyway maybe someone might get in touch (but you might have to be more specific as it is a pretty large field).
*scratches head, not thinking of any specific names (not me though)*
There have been quite a few threads posted on employment law topics so it might be worth using the search function, there are certainly threads about resignation periods and unemployment.
The Verbraucherzentralen can often offer good advice (often for free), if you are a member of a trade union or professional organisation then legal advice might be available through them too.
Students at certain universities can get free legal advice from their university too.
The ARD Ratgeber Recht website is a very useful tool (German only), as is
their database.
Katrina