German certificate B1 "Zertifikat Deutsch" is a basic must have certificate for your German career. It is internationally recognized certificate and confirms your knowledge of German on level B1 of common european framework of reference for languages - which is often the minimum required level of (additional) foreign language for business. This is very important certificate. B1 means that you are able to participate in the conversation, express your opinion, correctly understand important informations in reports, radios and newspapers, and know how to express themselves in writing. In Germany, the Goethe-Zertifikat B1 serves as proof of German skills in acquiring of German citizenship - a naturalization certificate.
Preparatory courses offers usually Goethe Institut. This cultural institute of the Federal Republic of Germany has a global reach: there are 160 Institutes in 94 countries. Similar institution has also Austria or Switzerland. In addition to that, you can also use some private language schools. B1 level can be achieved, depending on the circumstances, after 300 to 650 group lessons. To be ready for this exam check out following sources.
As always, the vocabulary is foundation stone for your success. You can make some grammatical or spelling mistakes but if you do not have what to say, you done. Directly from Goethe Institut there is perfect book of necessary vocabulary. Wherever you are, you can very easy learn with German with Moritz App on your iPad (download for free) - there is over 2,500 example phrases and sentences, memory games, all with native speaker. On the road use free German flash cards for your smartphone. Both of them have the required vocabulary of nouns.
Self-study is always hard, but there are many helpful books. Nice Coursebook with two Audio-CDs is this one:
Good planing is crucial, so study carefully following sample test from the exam. First, check out modules of the exam and sample test from Goethe Institut here or here. Then look at other sample tests with mp3 audio and watch video from the oral examination.
And finally, take a look how the certificate looks like after you pass the exam :-)