It is a good idea to position your probes where they're going to be in the water, and leave them there for a couple of days to 'season', especially the ORP and conductivity probes. The pH probes can be calibrated soonest. It's advisable to use the single use standard packets and keep that at tank temperature. Be prepared for the first calibration to sometimes not give satisfactory reading, requiring recalibration. It's always a good idea to have extra standards packets, very few people can get by on just what's provided. The conductivity probe can be very tricky to get properly calibrated. Make sure that it is blotted dry for the zero reading, and that the standard is at tank temperation for the second reading. This may also need to be repeated. The ORP probe generally doesn't need calibration by most people unless you're planning on running ozone. You should see the ORP reading gradually rise over as much as 2 weeks as it adjusts to your tank. You didn't mention the temp probe but I'd also strongly suggest calibrating against a known high quality handheld thermometer.
