Would anyone be able to explain to me the race construction kit and how you get your horses into it, how you actually upload your exported horses to the league and how you choose which races it runs in?

we use ck to trial our horses to find out which is best
go here to see how to do it viewtopic.php?f=16&t=4866

I think the best thing to do is make an account in TOM and view for yourself. And if you have the game then download the races from previous weeks and watch them.

To give you an example of the races we have this was from week 2 when all the maiden races were run. There are usually 30-35 races per week.

If I want to run horses in the flat uk league and the jumps uk league do I need to register twice?

No, you can switch between the leagues on the upper right side.
Bu t u are not allowed to upload a horse twice. When it runs in flat league it can't race in the jumps league.

It's just that it says I have to choose a home league on sign up page what does this mean?

does not matter that was when uas lge was running you had to choose usa or uk as home

Ok thanks