Often I want to buy some anime or manga, but after a long time of searching, I find out, that the manga/anime isn't translated yet. Is there a website where I can find information about whether an anime/manga is licensed and/or translated? At least in English, but if there's a source for German translations, too, I would be very happy!
I typically look up this information on Anime News Network's encyclopedia. They tend to have licensing information pretty well covered. They pay attention to the announcements made by the major licensing organizations and typically write brief news pieces for each release, and more data about the licensing is added to the encyclopedia entry as it becomes available. I can't comment on their reliability in any language other than English, but in English they are usually pretty good. I can't comment on how reliable they are for manga.
Other anime indexing services also tend to have information, though it's often more sparse. MyAnimeList and AniDB both sometimes have licensing data. In MAL it's listed with an L in the "Producers" section. In AniDB, they typically have a link to the website of the licensing company. In both cases, I was able to find some licensed anime which weren't listed as such, so in my opinion these are less reliable than ANN. These sources typically only list English licenses.
Typically, Wikipedia articles also include this information when it becomes available, at least for English releases. However, these are maintained by fans, and usually link back to various news articles anyway from ANN, MAL, etc. so they may not be as reliable.
Finally, if there's any doubt as to whether a specific company has licensed a particular anime, you can usually check their website. All licensing companies that I know of have a list at least containing all anime that they have released, and most also list future releases.
Wikipedia has a list of English licensed manga.
I know of no standard list of manga available, but a google search for buying/downloading manga in
google.ca will yield English manga sites, and
google.de, German manga sites.
If you can get to a manga shop or a comic book shop (less likely, but some comic book shops do stock translated manga), ask them for information on new releases in English (or German if you are in Germany) as they will have details on new manga and will stock in the native language of course.