In this paper we propose a generic methodology to study the correlation between nodes interactions in complex networks and their organization into groups called communities. We illustrate it on citations in a blog network. We first define a homophily probability evaluating the tendency of blogs to cite blogs from the same community. We then introduce the notion of community distance to capture whether a blog cites (or is cited by) blogs distant or not from its community. We analyze the distribution of distances corresponding to each citation link, and use it to build maps of relevant communities which help interpreting blogs interactions. This community-oriented approach allows us to study citation links at various abstraction levels, and conversely, to characterize communities with regard to their citation behaviour.