Hey, can you tell me which ones you got stuck on? I can try give a bit of help either here or in the book.
One thing about those though is that if you can't complete them, then just move on and maybe mark it for later. You should try to figure them out for a bit, but sometimes you just can't and have to come back to it later.
Finally, make sure you have this latest version of the book. I added a small section in the beginning which talks about this, so you might have an older version.
EDIT: Oh I'm assuming you mean the Extra Credits. The lessons you should try really hard to do and figure out before moving on. But skipping Extra Credit is quite alright.
One thing that really took me a long time to figure out was that using python on Windows XP is something different than using it on a mac or on linux. Some things just don#t work or at least work slighlty different. Maybe you could ad a more explicit warning about that.
One thing you might add to the book is a “what to do if I get stuck” section. I think especially pointing people (even newbies) at IRC is a good idea, as long as there's a bit of elaboration about how to effectively ask IRC questions.
Freenode’s web client http://webchat.freenode.net/ isn’t perfect, but it should be figure-outable when accompanied by some simple directions.
One thing about those though is that if you can't complete them, then just move on and maybe mark it for later. You should try to figure them out for a bit, but sometimes you just can't and have to come back to it later.
Finally, make sure you have this latest version of the book. I added a small section in the beginning which talks about this, so you might have an older version.
EDIT: Oh I'm assuming you mean the Extra Credits. The lessons you should try really hard to do and figure out before moving on. But skipping Extra Credit is quite alright.