I do recommend us voting more as a community, however, up votes and down votes both should be used more. Because voting is tied to quality, we should use it but be aware of what it means for the site.
Up voting good well asked questions on the site will make them stick out and show off what useful questions we have have here. Down voting questions that are confusing, roundabout, or not useful helps us monitor, inform, and refine the question we have and display to the outside world. We can also always steer the OP into a better quality question by explaining our down votes.
Note if questions are not answerable, closing them makes more sense than down voting. We should still answer these questions, but showing quality helps us a lot. There will also always be questions in the middle. In a perfect world, every question would get a vote, but there is grey area. Also note that voting while important is still in the individual's hands and as such there's not a blanket statement we can give with voting on specific questions and answers. We can only really state guidelines.
While we're on it, off topic questions and answers are kind of outside the scope of voting and we should keep that in mind. We should deal with them though other means like closing, migration, or deletion. Down or up voting off topic content doesn't do much for us as a site.
We're also fighting something else when it comes to voting which is the hot network question effect in which the whole network will see questions on the sidebar and come here and vote. When they do, typically they vote more on answers than the questions themselves and do not have the ability to down vote due to them needed 125 rep on the site. This leads to a lot of the lopsided voting on newly asked question that seem to get a ton of votes and views out of nowhere.