In order to sign a petition,you go to the petitiion you want to sign and click on the SIGN button found after you read the petition.
Here is an example. click here to list of groups and choose one of them e.g. federal legislative. clickon it and it will provide a list of all the petitions under that category.
choose the petition you want to sign from that list. e.g. 1.do not change social security
at the end of the petition you will click on the sign button
This button does not work. Go to groups , the category, and then the petition you want. That is all there is to it. .