Problems with Shortcode in normal posts [newbie]

Dear mates, I am totally new to WordPress on my own home server.

I tried to use the WordPress shortcodes in one of
my posts,
e.g. like
[youtube=…]

but got no correct result. The shortcodes used were not
interpreted as I would assume.

I switched off all plugins and switched back to the wordpress 2010
standard theme.

My questions are:

1) What could be the reason for this problem?
2) Is there somewhere a list of standard shortcodes for this release?

By the way: I also tried some latex plugins and had no success as well.

So either I missed totally the conception or there is really something
wrong.

Would be really great if somebody helps me out of this mine field.

Thx a lot, mates, in advance and sorry in case I should not
use the terminology correctly (I am really a complete greenhorn)

Cheers

Stephan