OK beand new on hear first answer was solid and I want to add my experience.
The most important bit of advice i think i can give is know and understand the records you own already.
For example. make sure you remember what label it is, this could lead you to try some other stuff on the same label (this works slightly better with smaller labels granted) Make sure you know who played on that album, its all well and good knowing its a particular band but if you love a bassline on an old 45 or album or whatever, find out who the bassist is, find out what else he played on or just remember his name when you're digging, one day you see his name on another record but with a different band... BOOM you just got turned onto something else completely.
Don't let genre dictate! ok so you like funk, but there's a ton of the funkiest music that has no relation to that genre, for example some prog rock has the funkiest drum breaks etc. Always remember genres are created as a generalisation to market something, your ears don't listen to how a tune is marketed, it listens to what it likes.
I could go on all day but I think the final thing is use your gut and instinct. When you start out this can be really hit and miss... infact it can always be hit and miss but don't ignore your head when you see an interesting cover art or read some interesting text on the back of a sleeve. Sometimes you come out with crap but a lot of the time you get turned onto a whole new thing just by luck and some judgement. To me these are the best finds and the finds that are the most exciting. I love finding those tracks that I've been looking for for months but I love the ones I never knew existed more! Plus with the instinct thing if you're digging in a dusty old place or charity shop bin where things are 50p or a pound you can afford that loss just for the fun of it.
Keep vinyl alive people we need it!