Most of the conferences in Computer Science publish proceedings with Springer, IEEE or ACM (even though there are several dozens which self-publish or publish elsewhere).
All three publishers have lists of upcoming conferences:

**Springer** 

LNCS: http://www.springer.com/computer/lncs?SGWID=0-164-12-73665-0

CCIS: http://www.springer.com/series/7899

LNBIP: http://www.springer.com/series/7911


**IEEE**

http://www.ieee.org/conferences_events/index.html

**ACM**

http://www.acm.org/calendar-of-events

Other great resources are mailing lists:

**Mailing lists**

DBWorld https://research.cs.wisc.edu/dbworld/
AISWorld http://www.aisnet.org/AIS_Lists/publiclists.aspx
ACM SIG-IR list http://www.sigir.org/sigirlist/
ECOOP info list http://web.satd.uma.es/mailman/listinfo/ecoop-info

Beware of conferences which do this just for money and not for disseminating knowledge: 
http://scholarlyoa.com/publishers/
This being said - of course the best way is to ask colleagues working on a topic related to yours - like your supervisors, post-docs from your group etc.