The KC publish all the forthcoming affiliated trials for the season earlier in the year, if you contact them they should be able to send the list to you or order the relevant issue of the Kennel Gazette (I think it was July but I've just moved and don't have it handy to check). Otherwise you'd have to pick which club(s) you wanted to attend and get in touch with them for the dates. Some trials are better for spectators than others, at some you might not actually be able to see anything and they also often take place on weekdays as well so you'd need to check that out too.
The Kennel Club have their own trials, the Cocker stakes this year are on 22nd and 23rd December in Norfolk. I'd probably recommend you go to the Championships though, it's got the best set up for spectators as it attracts more than most 'normal' trials (although still relatively not that many), it's being held in Dumfries in Scotland in January.
Let us know when you're coming and where!
