One or Two Spaces?
I know that today when writing the common decision is to use one space after a period. However, when reading on the web, it’s better to use two because it makes it so much easier on the eyes to discern where one sentence let’s off and the next begins.
The choice of course, is yours to make. However, consider this. You want your readers to come back, and often. If you do these little things, that they may not even realize, that help save eye strain, they appreciate you can come back to read more.
Fonts
San Serif fonts such as Arial, and Verdana, are easier to read on a computer screen. The easiest is Verdana. It looks like Arial – a nice, clean, straight font, but it has more space between the letters. The problem with the Arial font is the letters are too close together and when you use an “r n” combination it looks like an “m.” This also plays havoc on scanners, which are not very smart and can’t actually read words.
Serif fonts are great for Headers and Subheaders – if you just have to have them on your website. But, leave them out of the text zone (reading area) and stick to Verdana, your readers will thank you.
Examples
Times New Roman is a Serif font (having a tale added to the letters) and is easier to read on paper, but when read on a computer monitor the letters tend to “pixellate” (fuse together) so what you are reading is harder on the eyes.
Arial is a Sans_Serif font (no tales – straight edged letters) but, the letters are close together and can make reading on a computer monitor just as difficult as a Serif font. Especially when you encounter a “r n” (rn) letter combinations which often looks like a letter “m”.
Verdana is a Sans Serif font. The letters are spaced farther apart when compared to Arial, and can make reading on a computer monitor easier than a Serif font. This is especially true when you encounter “r n: (rn) letter combinations.
The above samples were all done in 14pt font size. As you can see, there is also a difference it the size of the actual characters using a fixed font size which is usually set in the page template for the website.