I'm a non-EU with B-Permit. Have applied for a Schengen visa (SV) at the German Embassy in Bern 3 times. Every time there was always a surprise for me, so I want to share it here:
1. as of this year, they are very strick in implementing the biometric photo (they used to accept the photos made at the cheap photo maschine). So better get it done in a photo studio and show them what the German requirements are (France, Italy, etc may have other photo requirements).
http://www.bundesdruckerei.de/de/bue...b/2_1_2_b.html
2. whenever possible, get the invitation letter mailed from Germany (the embassy staff like to see a dated post stamp)
3. make sure you bring enough cash with you (they don't accept EC- or credit cards). To be on the safe part: find out what the current fee is and bring double as much cash (you'll never now if they'll change the fee in the last minute).
4. last time the embassy staff asked to see my health insurance card (bring this with you!), and he complained because there is no EU symbol on the back of the card. I showed them my insurance certificate which states that my insurance covers me worldwide. The staff said "but worldwide does not necessarily mean EU"... I thought "how stupid can this person be?". I told him that this certificate was acceptable in my last two applications. Then he went to ask his other colleagues and found out that this certificate was indeed acceptable.
5. seems like the validity of the SV depends on the staff mood. My first visa was valid for 11 months (max. 90 days of stay in EU countries). The 2nd visa was valid for 3 months (max. 30 days). The third was valid for 7 months (max. 60 days). I failed in my attempt to change their decision. There is no transparency on this decision. The funny thing is, the staff said that starting 2007, they only give SV valid for max. 6 months. But I guess he miscalculated and gave me 7 months instead

. My colleague went a month later and got only a 6-month SV. His wife's SV application was rejected because she had just been less than 3 months in Switzerland and this was her 1st SV application (her passport shows that she never traveled outside her home country before).
Hope this prepares you of what to expect at the German Embassy (beside standing inline outside before they let you pass the metal detector and enter their waiting room in the basement).