Clicking the New Wave button at the top of your Inbox will create a new Wave and open your first blip, it's customary to make the first blip the page Title so go ahead and create a page title and using the H1 button set the size to H1 a nice big Title. You can also add a short description about the purpose of the wave or any instructions to other wave members.

Inviting others to join your Google Wave

To invite other people to join your wave and assuming you already have some contacts, click the + symbol at the top of panel 4 (The Wave) it will be to the right of your Avatar (account image) click each of the people you want to add to your wave and the wave will be sent to their Google Wave inbox ready for them to take part.

Receiving a Google Wave

When another person adds you to a wave it appears in your Wave Inbox automatically and within moments of you being added to the wave, new waves appear at the top of your inbox and can be opened by double clicking on them, if a wave already has activity it will have a green indicator with a number in it to show how many unread blips are present.