You should probably consider creating an editorial calendar to coordinate your Facebook, Twitter, blog posts (either on your own company's blog or guest posts on other related blogs) and press releases. This will help you keep your topics in sync with the upcoming website launch and other important company events and initiatives.
Here's one example
Since you're a B2B firm you might also consider setting up a company page on LinkedIn. Some B2B companies are reporting surprisingly good results from LinkedIn. Have all the company employees who have a presence on LinkeIn "follow" the company page to ensure that any status updates made to the company page get broadcast to their contacts. (You'll also want to include a LinkedIn chicklet on your blog and your website, along with the FB and Twitter chicklets to encourage those outside your own company to follow as well.)
If you do establish a LinkedIn page, you'll also want to add that to your editorial calendar.
I've also lately been using an online tool called Trello
that looks as though it will be very useful for keeping track of all those great story ideas I get when I don't have time to actually write them.
It's free, and you can add other people from the company to collaborate on story ideas. Combining Trello and the editorial calendar seems to be working well for me.