Thanks, Sanderd17,

for your friendly welcome here.
The more I look at the details of my home town, the more I find details one could add - based of course on the existing lots of stuff others have already done. The speed limits and adresses represent, as you say, a lot of work. Right now, I'm focusing on missing pathes and residential roads and their names. An interesting exemple where my local knowledge is probably advantagous is http://www.openstreetmap.org/browse/way/107000959
This road is connected at both ends to the neighboring roads - in Bing, one of those connections is absolutely "invinvible". Its a really narrow connection between two houses - but it exists. I´ve been there...
BTW speed limits: The example you have given is complicated to map: There is a 30 km/h speed limitation that is only valid on work days (MO-SA in Germany) from 7am to 5pm. Otherwise, its 50. I don't know yet how to map this. Other issue I have as a rookie: the correct classification of roads and their surfaces is a mess (for me)
compdude is probably right - at least with respect to me: there is some work to do..
It's more complicated than I thought - but I'll do my best..