To add people to your wikispaces, you have to be the person who created the wikispaces in the first place. If you are that person, you can click on the "Members" option which is in the upper right hand corner of the screen.
Then you are able to click on "Invite People" which brings up a box where you have to fill in the email addresses of the people you would like to invite to the wikispaces (similar to sharing documents on Google Docs). You can even add a message if you want.
Once you fill in the email addresses, press "Send" and those people will receive the invite.
Then you are able to click on "Invite People" which brings up a box where you have to fill in the email addresses of the people you would like to invite to the wikispaces (similar to sharing documents on Google Docs). You can even add a message if you want.
Once you fill in the email addresses, press "Send" and those people will receive the invite.