If you haven’t done so already, look for a webinar system, e.g. WebEx or GoToWebinar. I am now looking at Google+ Hangouts OnAir (Google+ and YouTube) as it is free and you can broadcast globally.

Pick some subjects and find people amongst your friend and business contacts who know something about these subjects. You may need to train them to use the webinar system that you choose as they may not be as knowledgeable as you are about webinars.

You do not need to have many guest presenters at each webinar, 2 is about right and you need to tell them what you want them to cover. The people you choose may see it as a marketing opportunity for themselves or their business so you will need to be clear about any branding on the presentation and what your presenters can say about themselves. Otherwise your webinar could turn into a long commercial that turns people off.

To get people to attend you need to market your webinars, offline as well as online.

@matthewhall, in regards to the platform conversation that  @philip started, there is also ON24 and Informz (more association-oriented). I use WebEx now and find it a bit unwieldy on the admin side.

We publicize our events via email, Twitter, Facebook and LinkedIn to our members. A few of our events are open to everyone so the social media aspect tends to produce good results. In March, using our full contact database and a supplemented list, we had over 200 people register for our research webinar.

Make the event copy enticing and offer images/snippets from the presentation to encourage registration. On Facebook, pin the event to the top of your page. Encourage the presenter, if someone other than you, to promote the event.

It all depends on if you want quantity or quality. You may have a large attendance but very few will be interested in buying (i.e. Mari Smith); while a select audience might be more apt to inquire more about your services (i.e. C-suite only).