The resteem button is next to the upvote. Resteeming is important during the voting process because if a good post is drowning in the new tag because no whale has spotted it, via the resteem the post arrives as a new entry under the new tag again, enhancing the possibilities that it will be spotted. It is a great way to promote the work of yr fellow steemers. The more people resteem, the more the attention of a whale is drawn to the fact that this is really something worthwhile paying attention to.