Well, C doesn't really compare to Python, Python is a language on it's own.
But you can program like C in it, since it has free functions.
One of the core ideas you have to grasp is the fact that nothing is sacred.
class dummy:
pass
d = dummy()
del dummy
# dummy doesn't exist anymore!
print d
print d.__class__
dummyReborn = d.__class__
d2 = dummyReborn()
print d2
That's how nothing is sacred. ;)
Other than that, follow a couple of Python tutorials.
But only follow the standard library and language, most api's aren't exactly usefull in BC. Also, quite a lot standard py files (uncompiled python files, see the SDK for the all the stock Python files in uncompiled form) aren't included, but you can include them by yourself in your mods.
Also, the Python version is 1.5.2.
Basicly, the only api's you need to learn for BC are App.py (the interface with BC) and the Foundation, after that, it's just what you need to use.
I can advise to always run in -TestMode and in Windowed Mode (see Graphics options after you start in -TestMode). In -TestMode you can access the Console (basicly a Python interpretter, except that you need to type print for everything you want to get a reply from).
Even more info, you can only read/write from files in scripts/Custom/ this is a security thing.
And last 3 pieces of advise, try (failure isn't bad, just try), snoop around in scripts (stock BC and mods) and ask specific questions when they arrise.