To appeal to the widest possible audience you can always elect to use straight text, but by designing your page while keeping in mind that many of the HTML extensions you use will be ignored by some browsers you can balance making your pages look the way you want them to, but without relying so much on proprietary tags that you exclude some from even seeing your carefully crafted page. You might be surprised how often the subtlest difference in interpretation can cause your perfect Navigator page to look like crap in Internet Explorer and vice versa. If there's a page you think you want to copy, feel free to do so. You can either save the page to your own drive, or view the source on-line using your browser. Obviously, you can do that with any page's source that you happen across, but please do not use any coding or tags without permission.
Some programmers are more protective of their work than others.
In many cases, you will find that all they ask is that you keep their internal authorship information within the source on your page. It is important, also, to remember that some people make their living designing web sites. Also, copyright issues are often involved with the writing that appears on a page. It is always best to ask the Webmaster before you may copy something from their site.