I started one of their kits here...
Mont-Saint-Michel
Have a read - most of the issues are maybe common. This one is now on the shelf - i got sick of spending more time figuring out what to do, then actually building. Kit was pretty complex, which may be part of the issue. Will resume it sometime though.
Suggest you go slow and figure out how each construction step goes. In the kits I have/have done, the pieces on a Page roughly relate to steps in construction. Roughly!
As you cut out the smaller parts use a pencil and label them. Mark joining edges maybe. When the pieces are uncut everything often looks clearer, but once cut out things can get confusing.
Scan the pages in case of a hashup - you can reprint a part if needs be.
I will post here if I can think of anything else that may help.
Main thing though is just start........and take it slowly and carefully!
Good luck!