When would I know that it is time for a valve adjustment? What sound should I hear from the engine? Thanks.

 

Check your service manual, it tells you when each part of the servicing should be done. I did my bike last year and my m8's also. My bike now has 40 thou miles and my m8's 24 thou miles.

If i remember right they should be done every 16 thou.. You'll hear a rattle from top end. If you have ever had an old car with manual adjustable tappets, it's the same sound.

The valves are screw and lock nut. Quite easy to do if you have some mechanical knowledge

 

It sounds great when cold but after it warms up I hear a ticking noise coming from the engine, I am going to buy the tool for the valve adjustment and probably give it a go in a couple of weeks. I hope it's the valve adjustment.

 

Valves can go either way. They're louder when they're loose, but when they get tight they'll quiet up. That's bad.
If you don't know when they've been adjusted, I'd just go ahead and do it. It's simple enough, just take your time and double/triple check the clearances after locking them each down.

There is a how-to on adjustment here... and the factory service manual spells it out pretty well.

As far as the special tool... you can use a deep well 10mm and grind the sides down so you can grip it with vise grips or a wrench to get on the lock nut. Then just use a long allen wrench down the center of the socket to adjust.
That's how I do it. I think the special tool was kind of expensive if i remember correctly.