Since your biography page is the page that tells your readers who they are reading about you should link to it from your entries. Of course, you don't have to if you really don't want to. My reasoning for linking to it from your entries is this; if someone is reading one of your entries about your son and they don't know who your son is, they can go to your biography and read what you have written about him.
Whether you link to this page from your entries or not you should definitely link to it from your homepage. This is very important because when a person finds your site they will not go on to read your site if they are not interested in you. The best way to get them interested in you is to tell them who you are. You do this by linking to your biography page where they can see it clearly.
Also place a link on your biography page back to your homepage. If the reader has read through your biography and has liked what they read then they may want to go back to your homepage to see what else is on your site for them to look at and read. This link should be placed in a place this is easy for them to find.
You will also want to link to your most current entry or your most current archive page of entries. If you have a page listing all your entries for the current month then this may be a good page to link to from here. This is for the same reason as linking to the homepage from here. If your reader likes you and wants to read more they can quickly and easily get to your entries to fulfill their desire. If they can't get there then they may leave your site altogether.
If you have a Webcam, picture album or anything else on your site you may want to create a small link box for linking to these pages. This is totally up to your discretion. As long as you have linked to your homepage and your entries the rest is optional. Link to whatever you feel is necessary to add to the flair of your biography to let your reader know who they are reading about.
