Users are advised to read :-
/usr/doc...)man chat and man pppd to explore these)The best general starting point for Linux documentation is The Linux Documentation Project Home Page
Whilst you can use this document to create your PPP link without reading any of these documents, you will have a far better understanding of what is going on if you do so! You will also be able to address problems yourself (or at least ask more intelligent questions on the comp.os.linux... newsgroups).
These documents (as well as various others, including the relevant RFCs) provide additional and more detailed explanation than is possible in this HOWTO.
If you are connecting a LAN to the Internet using PPP, you will need
to know a reasonable amount about TCP/IP networking. In addition to the
documents above, you will find the O'Reilly books "TCP/IP
Network Administration" and "Building
Internet Firewalls" of considerable benefit!
There are many Linux mailing lists that operate as a means of communication between users of many levels of ability. By all means subscribe to those that interest you and contribute your expertise and views.
A word to the wise: some lists are specifically aimed at "high powered" users and/or specific topics. Whilst no-one will complain if you 'lurk' (subscribe but don't post messages), you are likely to earn heated comments (if not outright flames) if you post 'newbie' questions to inappropriate lists! This is not because guru level users hate new users, but because these lists are there to handle the specific issues at particular levels of difficulty.
By all means join the lists that offer open subscription, but keep you comments relevant to the subject of the list!
A good starting point for Linux mailing lists is Linux Mailing List Directory