Virtual Assistant Forums:

VANetworking

International Association of Virtual Assistants (IVAA)

Scheduling/Appointments:

AcuityScheduling

TimeTrade

ScheduleOnce 

Automation:

Zapier

IFTT

Presentation/Videos:

Presentermedia

TechSmith/Camtasia

TechSmith/Jing

Time management:

Asana

Toggl (Asana)

Google Calendar

Communication Tools:

Google Voice

Skype

Email marketing:

Leadpages

AWeber

Customer Relationship Management (CRM):

HubSpot

Virtual meetings/ Screencasting:

GoToWebinar/GoToMeeting

Google Hangouts

Zoom