If I install WP in a folder such as www.mysite.com/wordpress, that means a visitor would have to visit that to see my content, right? As opposed to, if it's installed in the root, he would simply need to visit www.mysite.com. Which is the best way, from a user's standpoint but importantly, from SEO standpoint? I just installed a new site and put it in /wordpress/ but I have another site and I put it in the root. I am not sure if it's trickier to put it in the root... seems I recall that I had a little trouble doing that.
it doesn't matter. all depends on how you want to configure your site. for example, you can have root a webportal, then have some folders for blog, forum, store and so on.
It really has no bearing on SEO, it's all about how you want it set up. Just remember that if you install on a folder, it doesn't have to be called "Wordpress"..you can name it anything that you want.
I agree with anyone here, but based on my own experience, i would prefer in my main domain, not in a folder. However you can installed it in a folder and access it with your main domain URL
I put myne in the root directory. Though if you have a main site and the blog is separate then put it in a folder like www.blahblah.com/blog