I feel like almost every law firm I've built a website for in the last year or two has asked me about having a blog. I typically tell them all roughly the same thing. I believe that the content on your website should be the number one priority. This keeps your efforts in one place, instead of diluting them across multiple platforms.
New content is benefial to your website, absolutely. So the question isn't as simple as "are blogs good for SEO?", the real question is "Do I have time to write meaningful content on a regular basis?".
If you are going to have a blog, do not make the mistake of almost setting it up and then forgetting about it for weeks, months or years. Meaning, until you can figure out how to have a nice looking blog that looks like some time has been invested into it, just don't publish it. That might sound rigid, but honestly, if you didn't even have one or two pages written, was it really time to start shopping for a blog?
Yes. New content is probably the MOST important thing you can do for your website. This, more than any other reason, is why I typically encourage people to focus on their websites instead of starting a blog. Unless you have an unlimited amount of time and great ideas to write about, it's going to be difficult to consistently provide new content for your website as well as your blog. On the other hand, writing sub-topic pages for your core practice areas can be helpful both in driving new potential clients to your site, but also making it clear to visitors that you help people in their specific situation.
Blogs can be successful with careful planning, a solid budget and a high level of dedication to the blog. However, I think it's best to define "success" as having an ability to add content to your blog and then to feature that content on certain sections of your site. That means there's a place on your website that links to "news" or "recent case updates" or some other section you're actually updating through a blog. Again, have a plan. If the entirity of your throught process was "I think I want a blog because they're good for SEO" then just skip it.
Wordpress software can be helpful for pages that you know your'e going to update frequently. Newsletters, recent results and testimonials are all things that would make a lot of sense to put on your blog, and then have links from the site to the list of the most recent of each category.
A lot of providers will build your entire website on Wordpress. There's a lot to think about before considering that. I am able to build entire websites on Wordpress, but there is a complex exchange of upside and downside. To read more about it, see this article: "Should I have my law firm website on Wordpress?"
There are a lot of ways to do this incorrectly; if your law firm's aim is to start a blog on Blogger, Wordpress or another free platform, re-publish content from other writers, link it to your website and watch the great result roll in, I would encourage you to rethink your strategy.
Buying a blog from a company like FindLaw is very likely going to cost you more money than it's worth. Finding time to create content is difficult, and most law firms are more in need of good core content on their site than they