A notary is a kind of lawyer who can help you with a number of different things, though they're most commonly needed to do the legal work when you move house, incorporate a company or perhaps to certify your signature on documents that are being used abroad (not common for the UK, but relatively so for the USA).
Notaries are strictly controlled by the Bavarian government and are always supposed to act and advise you in a completely impartial manner (they can, therefore, represent both parties in a house purchase for example). A notary's fees are also set by law, and so there is no advantage to be had in 'shopping around' to try and find the best price, as they should vary by no more than a couple of Euros.
Unlike in the USA notaries in Germany are professional people who have undergone years of training - usually notaries are selected from the top few percent of law graduates. This is reflected not only in their level of knowledge, but also in their fees, which can be relatively high.
There are many notaries in Munich, and they can be found in the Yellow Pages, or online. Dr. Beate Kopp at the notaries chambers at Leopoldstraße 18 is a fluent English speaker, and also right in the centre of town (just a few hundred metres from Universität U-Bahn).
Notaries usually operate on an appointment only basis, and so it is wise to phone in advance. Fees vary enormously depending on the amount of work involved, and also on the value of the transaction in question - if you can therefore conceal the value from the notary, you may pay less fees, although this is sometimes impossible to do (for example in a house purchase).
For some work, your consulate may be able to help you - this is especially true of certified copies, and from time-to-time the consular officials may be able to certify your signature. This is only the case for documents that you will be sending abroad. The consular system is much cheaper, although you may have to wait a little longer for an appointment. Notarial acts from Germany being used abroad MAY require legalisation by way of the apostille - your notary can get this for you - in Munich the Amtsgericht issues apostilles, and the process will take a couple of days.
Related pages: