Wordpress is an awesome CMS with a ton of great plugins. We recommend using wordpress for our clients and then do a full SEO audit before making the site live.
There are plugins for SEO (someone mentioned yoast) but if you're serious about SEO you really need to know/research what the best ways to optimize are. Yoast, for example, doesn't set meta keywords on your homepage. The meta keywords may play less of a role with Google today but they still contribute to your keyword density and the other meta crawler search engines depend on them. I've never understood firms that only optimize for Google. They're definitely king but a couple of small additions will help in the other engines as well.
Wordpress is a great CMS, you still need great optimization to audit it once it's got the themes and plugins setup to ensure you're maximizing your search presence
