Before you can read or participate in any newsgroup, here is what you must have:
News messages are known as articles or posts. Once you are connected to the news server, your news software can download messages to read offline. Your ISP will only store a specified number of articles in a group - ask them to keep articles longer if they disappear too fast. You go adrift unless you ask!
Get started with Usenet and Canadian groups:
Some regional newsgroups begin with can (Canada), ont (Ontario), ott (Ottawa), etc. Usenet world-wide newsgroups begin with news, rec, sci, comp, soc, talk, and misc. Most news software has a search tool to help you.
Never post ads in discussion groups unless the newsgroup's FAQ specifically allows the practice! Posting ads in newsgroups that are intended for discussion brands you as a spammer and news administrators may delete your posts, block your account or even block your entire ISP.
Search the newsgroup names for "forsale" to find groups that allow ads.
Examples: can.forsale, can.atlantic.forsale, nb.forsale, ont.forsale, ott.forsale.other, kingston.forsale, tor.forsale.misc, niagara.forsale, van.forsale, nanaimo.forsale, vic.buysell, vic.forsale, calgary.forsale, misc.forsale.non-computer, rec.boats.marketplace (moderated).
There are options that allow you to download all your mail as well as unread news articles in newsgroups that you have previously selected. This will save enormously on connection charges, since you can read and answer mail and news offline, then send them all at once when you reconnect to fetch a new batch of mail and news.
Before you can do this however, you must first subscribe to some newsgroups, then select from the list for downloading. (Note that when you read a newsgroup from a hyperlink, it is automatically added to your subscribed list.)