To insert an image:
[img]IMAGE URL GOES HERE[/img]
To change text colour (you can change "red" to whatever colour you want to use):
[color=red]TEXT GOES HERE[/color]
To make text that links to a page:
[url]TEXT GOES HERE[/url]
To make an image that's linked to a page:
[url=LINK URL GOES HERE][img]IMAGE URL GOES HERE[/img][/url]
That should be about all you need to know.