The normal means of communication between wikipedia users is via the user talk pages.
To begin a conversation, always create a new section, and of course sign your name with ~~~~.
To avoid conversations being split over many pages, it is best to reply underneath queries. Then you end up with a threaded conversation, like;
First message here chzz (talk) 00:01, 1 April 2009 (UTC)
If the conversation is on your page, rather than the other users talk page, then you may want to let the other user know that you have replied. Go to their talk page, create a new section (called 'Talkback' or something), and put this in,
{{talkback|Chzz/help}} ~~~~
...which will look like this;
You can remove this notice at any time by removing the {{Talkback}} or {{Tb}} template.
Chzz/help (talk) 00:10, 1 April 2009
For more, see Wikipedia:Talk page
Best wishes, --~~~~