Songhue's right, the img code can even be as simple as:
<img src="URL">
The border="0" is the thing that gets rid of the annoying blue border around the image if you link it, so you only really have to care about that if you're making it link to somewhere. You can do that by going:
<a href="URL OF LINK"><img src="URL OF IMAGE" border="0"></a>
If you're using someone else's layout, they're probably already using CSS to create a default text style. Generally, I recommend using an external CSS stylesheet because that makes things really easy, but if you simply want an easy way to change text, you can do that two ways:
If you're using a <p> tag already for your text, then the easiest way to change it is:
<p style="color:#FFF; font-size:10px;">TEXT</p>
That'll change the size and color of your text. If you want to add more space between the lines of text, there's also a property you can add in there called line-height, as well as a property that is called font-family that will change your font for ya.
If you're not using <p> tags, then the easiest way to change things would be to just use the <font> tag, which would look like this:
<font color="0000ff">TEXT</font>
or
<font size="+2" face="arial" color="0000ff">TEXT</font>
The font tag is kinda the bane of all web designer's existences, but it's still a nice "quick and dirty" way to change things