To start a signature campaign for an altcoin, you should check out the services section. You'll see a lot of examples of current coin campaigns. If you're planning on paying out using altcoins, you should check out the altcoins services thread. It seems that nowadays, campaigns are using alts because Bitcoin is so volatile. First, you're going to need a lot of funds depending on how many people you want working. Then, find a manager in the services section (_Darkstar is a great option), and contact them letting them know that you want to start a Signature Campaign. Make sure you have the thread made and the signatures created as well, and then you'll be able to start up your campaign.