You might want to put a link in an entry you're writing, so people can click on the link and go look at something else on the web. First, you need its address on the Internet, its URL or Uniform Resource Locator. Go to the page that you'd like to send people to, select all the text in the little window at the top of your web browser that shows the URL of the page you're looking at, and then copy it so you can paste it where you want it (in a minute)... (You copy it by dragging the mouse over it or triple clicking in the window to select the address, and then using Copy on the Edit menu, or Command-C on a Mac, or Control-C on a PC to save it temporarily.)
If you're tagging yourself:
You type <a href="[And then you paste the address that you want the link to send people to in here]">[And then you type the text that you want to actually have highlighted in your text for people to click on in here]</a>
So what I actually typed to produce this sample link set up to send you to OlyBlog's home page looks like this:
If you care, href stands for hypertext reference, and the <a .....> at the beginning and the </a> at the end mark the beginning and end of the anchor tag that you're putting around the text in the middle, the text that actually shows in your post. (I think it's called that because it anchors or links one place on the web to another place.)
If you've enabled rich text:
You type the text that you want to have underlined and working as a link when people click on it, and then select that text. The little chain icon for creating a link will stop being greyed out, and then you can click on it and get a little window labeled "Insert/edit link." Put the cursor in the field labeled "Link URL" and paste in the address that you copied a minute ago, the one from the page that you want to send people to. (The little Target menu lets you have the link open that page in a new window, which people have to close if they want to get back to your post, or in the same window, in which case they have to use the Back button to return to your post.) You don't have to put anything in the Title field; if you put something there it will show up in a little tooltip label if a user hovers the cursor over that link in your post. Click Insert, and the editor should add the anchor tags around the text that you had selected.
If you're using the rich text editor, you can change the link by selecting it in you post and clicking the link icon again. You get the same window, but you can paste in the address again if you didn't get it copied right the first time, or change the title or how the window behaves, and then click Update to revise the tagging in your post.
If you're tagging yourself and the link doesn't appear at all or garbage bits of your tag appear too it's because you've got a typo in your entry somewhere. You left out one of the quotation marks, or one of the brackets, etc. Don't despair - sometimes you have to stare at it several times and curse a little before you figure out what you left out or put in that's not kosher. If it takes you to the wrong page, your URL address is wrong, usually because you didn't have the whole address selected when you copied it.