I'm a Text widget. You can write basic text in here, or if you know a little HTML, you can add things like links, or some bold text, even italics. In fact, there are default styles ready for any kind of markup you toss in here.
If you check the "automatically add new paragraphs" option, you won't have to add P tags around each block of text, which can be pretty handy.
To change the way posts appear on your homepage, login and go to Appearance > Widgets. Open the Home section, and edit the settings for the “Recent Custom Post Types” widget. There, you can change the number of posts that display, reorder them, and other options.