Thermometers - I Need Some Help

[HoomanSlave]

I'm a bit confused on where to place thermometers. I'm going to buy two digital thermometers (https://www.amazon.com/Zoo-Med-Digi...84&sprefix=digital+reptil,aps,383&sr=8-7&th=1) for my future dragon's tank. Where do I put the thermometers? Do I put one on the cool side wall and one on the basking rock?
I'm bad at explaining so I drew a cringy picture. The blue blob is the basking spot rock (or maybe branch), and the pink dots are to represent the thermometers. The green is for a hygrometer (I live in a place that gets very humid in the summer/spring).

Next questions

How often should I check the temperatures?
Are the temperatures likely to randomly drop/increase or will they stay pretty consistent?
My house is typically 65-70 at night, so I won't need a heat emitter/pad. Should I still get one just in case?
Is a bulb that emits both heat and light okay for the daytime?

Also, if anyone has bearded dragon book recommendations, that would be awesome.

 

[Silver dragons]

Hello, where you put the thermometers is good. You should check the temperature everyday. You can have a extra heat pad just in case but it is not necessary. Yes bulbs that create heat and light are good but you're going to still want a UVB tube bulb. I don't have any bearded dragon book recommendations but if you have any questions feel free to ask me!