I'm an apprentice electrician and currently trying to learn howto wire boilers,any step by step help would be appreciated and any simple steps when connecting in2 the main joinig/connection box that all cables go back 2 would be very appreciated

May be better you tell us what you know and we can add or correct as necessary.

If your learning , who is showing you?

What is your background before being an apprentice? Schooling?

This will help with the level of technical answers given.

OK,I know you take a 3 core from the cylinder stat and from the room stats back to a connection point,and I think a 3 core cable from the programmer,and 5 core flex from pump and boiler and a cable from the valve to the connection point,also a supply... I hope I'm right so far... once all the cables are at the connection point,I think all the earths go together and all the neutrals together,but I've never connected up any more than that,I know the clinder stat works the hot water and the room statsdo the heating,but that's as much knowledge as I have,so any help educating me about the lives would be helpful,thanks

OK I got a bit of what you know, but no answers on the other questions, so I will do the best I can.

I see from your words that you are most likely in the UK. Never having heard of a "cylinder stat",I did a quick search and found out that most of the sites that have something to do with it are from the UK.

I found this site from Honeywell, Systems
Really seems to do a decent job of explaining the various systems and the wiring for each.

This should help you.

As an apprentice, you should be asking the journeyman your working with as many questions as you can. And read, read, read, grab every manual that comes with any equipment your connecting and read it, most give wiring diagrams and sequence of operations for the systems.