Thankyou. The file size is now much better, especially for viewers using mobile devices or with slow/capped broadband.
There is no simple answer to your question. Resistor values are chosen according to the function of the relevant part of the circuit. In general, higher values are associated with low current parts and lower values with high current parts. Choice of value is often a compromise, bearing in mind such factors as circuit loading, thermal noise, gain, power loss, minimising battery current etc.