The trick is to stay under the radar, especially with a newer site. I’ve experimented with lots of different configurations over the last few months and noticed that its possible to rank for very long tails without any backlinks as long as the site is regularly updated with fresh content.
Older sites or sites set up on aged domains can take some backlinking, but less is more right now. Each site is an individual case, so its really hard to generalise over what is right or wrong. Sergej said it right – unnatural looking links can cause problems, so try and keep the link profile natural looking and err on the side of caution.