Resolved questions
Russian prefixes (за-,на-,по-,про-,при-,из-)?

As I read Russian texts, I often find words I ought to know, but with a prefix (like за-,на-,по-,про-,при- or из-). It seems to me that the unprefixed form is not used that often. My questions are now:
- What do these prefixes mean?
- Is there a general translation for them or do I have to learn all forms for each word?
- Do you know the equivalents in English or German?
- Are there more prefixes I should be aware of? (and what do they mean?)

Some examples:
I know the word "писать" but more often i find words like:
написать, записать, прописать, приписать, исписать

or the word "учить":
научить, проучить, приучить, изучить

and "смотреть" is mostly used as:
посмотреть, просмотреть

Additional Details:

Additional Details:

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Edit/Update:

Now i researched a little bit more and finally found something:
http://www.yearlyglot.com/finally-understand-those-russian-prefixes/
http://www.slavica.com/features/browning_intro.pdf

Thank you nonetheless for your answers :)