My 1999 Jeep Grand Cherokee Laredo will not turn over when I try to start it. No clicking sound - just nothing. The electrical is all fine; opens with keyless entry mechanism, lights go on, windows roll down. Any clue of what this might be?

I would use a jumper cable from the positive battery terminal to the starter to see if the starter and solenoid are good. If the starter works you probably are having issues with the ignition switch electric contact base. The part of the switch you put the key is the tumbler. Below that is the contact base where all the electric stuff happens . Yours is probably dirty or broken , but can usually be changed easily by taking off the steering column covers. You may need some special tools (anti -theft sockets or screwdriver inserts). The anti-theft screw and bolt tools are available from a lot of tool supply stores.