Legal matters
It is quite likely that you will never have to deal with any legal matters whilst living in Holland. Should the need arise, here's some information on matrimonial property, divorce, taxes in case of death, and legal aid.
Matrimonial property
If you get married in the Netherlands, all property and debts that either of you had before the marriage become joint property and debts once you are married. This can only be avoided by means of a (pre/post) nuptial contract.
Divorce
In the Netherlands you can file a petition for a divorce before the District Court of the district in which you and/or your spouse lives. If both of you have Dutch nationality, the Dutch courts can see your case. This is also true if one of you has been living in the Netherlands for a period of 12 months or more, or if one of you is Dutch and has been living here for a period of six months or more. In all other cases you can not file for divorce in the Netherlands.
Taxes in case of death
Under Dutch tax laws, the entire estate of non-Dutch nationals who die while living in the Netherlands is (also) subject to taxation here. Even those who do not live in the Netherlands at the time of death may be subject to something called "transfer tax". The criterion used for the tax is whether the goods had a strong connection to the Netherlands, such as immovable property. Treaties may provide (some) relief from double taxation.
More information on double tax relief is available from the Dutch Taxes and Customs Administration website.
Legal aid
Legal advice is not hard to come by in the Netherlands. If your income is below a certain level you can approach a "Legal Counter" (in Dutch: Juridisch Loket) for initial, basic questions. These are located in most larger cities.
If you then require the assistance of a lawyer, subsidized legal aid is available through legal offices. If you do not require subsidized aid, you can consult a lawyer, which are decidedly more expensive. Other sources of advice could be trade unions and social service counselors.
Your HR agent can provide you with some local information should you need to contact one of the above.
More information
There are two european helpdesks which could prove useful in a number of circumstances.
SOLVIT
SOLVIT is an on-line problem solving network in which EU Member States work together to solve without legal proceedings problems caused by the misapplication of Internal Market law by public authorities.
Citizens Signpost Service (CSS)
The CSS is aimed at EU citizens who encounter problems with mobility in the European Internal Market.
The CSS is targeted at the broad spectrum of problems which come with mobility within the EU, while SOLVIT only looks at solving misapplication of Internal Market law by public authorities. While aimed at a certain category of issues, they can actually help with many issues.
Sources: xpat.nl, wikipedia

