Hello,
you probably mean the “read more” link displayed at the post entries. This text is generated automatically by WordPress. You can change it, if you insert into the post content the following tag instead of the default “more” tag:
<!--more But wait, there's more! -->
You only must switch on the “Text” editor instead of the “Visual” editor to use this tag. In the following article, you can find more information about customizing the “more” tag: More tag.
Best regards
Tomas Toman
If you go into “Appearance > Theme Options > General settings > Content/Excerpt Displaying”, you also can set here the automatically generated excerpts (the first 40 words of each post) to be displayed instead of the full content.
Super ! work like a charm, thank you very much !