Hi Kevin, I've only just seen your post so apologies if you've already found these resources - I know it's been a while since you posted your original query!
I've just started trigbagging recently and the most useful resource I've found is TrigpointingUK (http://trigpointing.uk/trigs/search-adv.php) where you easily search for trigs by number or location. That'll give you the data for the trigs, including the condition of the pillar (if there is one) and the OS ref. There's also a site called Trigbagging (http://www.trigbagging.co.uk) but it's quite slow to load! But it does have a decent interactive map of all the trig points which can be useful.
I also use the OS Maps phone app to save a marker at the location of the trig I'm trying to find, especially if it's potentially hidden or the pillar has broken and so therefore isn't easy to find. That way I can minimise the search time when I get to the area! Some of my local trigs are in the middle of moorland plateaus, and take a bit of bushwhacking through heather and peat hags to find, so I've found the app be useful!
Have fun! All the best, Alex