We've put together a number of guides for the game which focus on stats and the specific effects of weapons, attachments, skills and criticals.
It has been commonly asked for this information to be added to the game - we're prioritising it and will get it implemented pretty soon (it definitely won't be next week's update). In the meantime, the guides should give you a bit more information.
PLEASE NOTE - the stats are always subject to change, so please don't get too attached to them!
http://steamcommunity.com/sharedfiles/filedetails/?id=426184313
http://steamcommunity.com/sharedfiles/filedetails/?id=426060708
http://steamcommunity.com/sharedfiles/filedetails/?id=426157068
http://steamcommunity.com/sharedfiles/filedetails/?id=426164041
Also check out a couple of game guides created by players if you're new to the game:
http://steamcommunity.com/sharedfiles/filedetails/?id=417490925
http://steamcommunity.com/sharedfiles/filedetails/?id=417381349