VATSIM CHARTS.PDF For UK Charts use NATS

Or, pony-up some cash for the best online (smaller filesize):

"EchoPlate is a simple online interface to the NOS Approach Plate Books scanned by EchoFlight. EchoFlight has freely provided this service since 1999, but now must charge a small subscription fee to offset the costs of bandwidth and production. You can Subscribe to EchoPlate for $5.95 every 3 months or $19.95 per year. We hope that this fee is affordable to all those who have come to rely on EchoPlate over the past few years."

By airport diagrams I presume you mean Airport Facility Diagrams