[GRASSLIST:2250] Help base gis task for beginner

[Eugene Prokopiev]

Hi,

I've read offical Grass Tutorial but it's difficult for beginner to 
understand which commands need I use to decide my task.

I've imported png image into grass location. What commands need I use to 
do following:

1. Draw contours of some territories
2. Describe this territories in SQL database table(s)
3. Draw contour(s) by SQL query.
4. Display selected contours with fixed scale (1:1000 for example) or 
with fixed map size and autoscaling.
5. Export map or part of map with selected contours into rast image.

Can anyone describe how can I do this step by step with full commands 
and params?

Thanks,
Eugene Prokopiev