As far as software recommendations to ensure easy communication, Yammer is a good one to setup your own private social network. One that is a bit less intense is Hip Chat which allows for company discussions and group instant message, I’d say more or less like an upgraded Skype kind of communication if you are familiar. And another free alternative to Skype for free video chat (with great screen sharing) is Google Hangouts. G+ has done a great job here, it seems to be more stable quality and connection than others. There are also many great remote time tracking programs like we are building at Worksnaps (http://www.worksnaps.net/www/) that keep people on track, accountable, and allow for complete transparency for all involved.

1. Google drive for collaboration/sharing of docs and other work 2. Skype for chat, group chat, and calling into conference calls. 3. Conference calls. We're using uberconference now, but it has been less reliable than is acceptable. We're going to try our own skype server. 4. We host our own git repos. 5. I do most of the project planning in org-mode and Redmine. 6. RT for bug reports

I like http://www.interviewzen.com/ to do 15 minute code quizzes of candidates where the hiring managers and HR are all dispersed geographically.

We have a very similar setup - with remote team members in Europe, USA and Africa at Resource Guru we find the Slack/Trello/Google Drive stack vital for our day to day communication and collaboration.

An alternative to skype/hangout is http://appear.in I find it works way better than the other, don't know why.

Can you detail why and how you use airtable?

Here are some tools recommended by HN users. http://www.hackertoolbox.com/tags/collaboration

NearFar (http://getnearfar.com) for chat and project planning; GotoMeeting for video conf, and Drive for docs.