I was going to be inspiring on my first advice post for the New Blogger Initiative, but a more prosaic topic seems in order. You've probably read blogs where there is a lively discussion on many or most of the posts. Tobold's MMORPG Blog comes to mind. This is a good indication of the health of a blog. As Tish Tosh Tesh so eloquently points out, blogging is a long-form social endeavor. On the other hand, Syp was ranting this morning on Twitter about the barriers to commenting on some Blogspot blogs. One of the great things about having a blog is the opportunity to interact with your readers through the comment system. Anything that inhibits this system interferes with that dialogue that you want to have with your readers. If you have chosen Blogger (the blogging site also known as blogspot.com, run by Google) you may have some barriers to your blog that deter potential comments.
Blogger has several options to be set by the blog author. My settings are visible in the screenshot below.
Sorry if it's small, click on it to see the full size. Notice the setting third from the bottom, "Show word verification." I have it set to "No." This is the CAPTCHA™ option. You've seen CAPTCHAs if you've spent any time on the Internet, a misshapen version of a word or characters that you must type in to verify your status as a human being. This is an annoying hoop that many people will avoid, depriving you of comments. I recommend not requiring them of your readers, which is why mine is set to "No." Blogger has a spam filter, not perfect, but sufficient, in my estimation.
Another way to avoid spam ending up on your blog is to set up comment moderation. I have moderation set up for comments on posts older than 14 days. I saw somewhere once that that is a good range, because spammers sometimes attempt to spam older posts. People rarely leave comments on my really old posts, but it does happen. I get an email notification when something comes in. Of course, I have options set to receive notices on all incoming commentary anyway. This is found on Blogger right under "Posts and Comments" called "Mobile and Email." The options on that page are fairly self explanatory, but there are small help buttons next to each setting, if you have a question.
Syp said that non-Blogger users have to input their basic info every time they want to comment, something that Wordpress blogs remember for you. I can't verify this easily right now because of browser settings at my office. I actually have to input my info on Wordpress from here, whereas on my personal computer running Firefox, I don't have the same issue.
One last thing that is a personal preference: I like to have my comments at the bottom of my blog posts rather than have a separate page like some folks on Blogger. To be honest, I am not sure what the purpose of a separate comments page is. Don't take your commenters to a different page. Let them comment in line with the post and other comments.
Bottom line (TL;DR): You want comments. Don't make it hard for real commenters, even if you have to deal with occasional spam.