Could you give me a list of relevant literature for seminar theme: Sociological aspects of suicide?

The most famous classic about sociological aspects of suicide is Émile Durkheim's "Suicide: A Study in Sociology", which was originally published in 1897. The book is still relevant and many studies concerning suicide has Durkheim as the starting point.

http://en.wikipedia.org/wiki/%C3%89mile_Durkheim

Steve Taylor's "Sociology of Suicide" (Longman, 1988) and Anthony Gidden's "Sociology of Suicide: A Selection of Readings" (1971) might be also useful to you.

But I think the most convenient way to start your study is by searching from the internet. We recommend Google Scholar, which has access to many scientific databases: http://scholar.google.com/

Good keywords for your search would be: 'suicide', 'sociology', 'social', 'sociological aspects', 'social aspects', 'statistics', and so on. You should compine term 'suicide' with one of the other keywords and then see and evaluate the results.

Statistics about suicide are available in WHO's website: http://www.who.int/mental_health/prevention/suicide/suicideprevent/en/