To directly answer your question; No. I can no provide dummy proof information for such a possibly complex issue.
First lets start with your network. You mentioned all those items you have, but how are they connected? Whats wired? Whats wireless? How does the switch factor in? Try to write us out a network diagram.
Second, what are the symptoms? Which devices won't connect? Wired or wireless? What do they say when you try to connect them? You say your game systems are laggy. Do you mean latency, as in multiplayer latency? Or throughput?
Third, what have you tried already? Do symptoms for a device go away when you go from wireless to wired? When one device acts up, do the others as well? Have you checked the router logs and see what they say?