i am looking at buying a dog for the first time since i was a child. can anyone give me info on how often dogs should have check ups with vets? do they need an annual/6 monthly health review?

You might find it helpful to contact the vet you plan to use before buying your puppy. He will be able to tell you about the British Veterinary Association health testing schemes for eye disease, hip displaysia, and the elbow scoring schemes which the parents of the puppy you get should have had done before being bred from. He will have the average gradings for the hips and elbows schemes for each breed which is listed as requiring testing. The vet will be able to advise you on the best time for your pup to have it's vaccinations done.
Once you have your puppy, it will go to the vet for vaccinations, and you will find that the vet will automatically give it the "once over". When you return for a booster the following year, the same thing will happen. While at this appointment it is a good idea to discuss with the vet worming and flea treatments which you will need to use. Your pups breeder will also advise you about these things.
What breed are you interested in? There may be an owner or breeder of that breed who could give you more breed specific information.
I think you need to register here, to ask another question, or talk to a breeder and/or owner.

I tend to take my dogs to the vets when they have a problem rather than at a set time for a check up, but I am confident that I know my dogs and can see when anything is "different" about them.

This might be a good thread in which to list the things we "notice" about our dogs and in which a change may indicate a visit to the vet is in order:

Ears - should be clean with no odour - smell or excessive wax should be checked out as should scratching or head shaking
Eyes - I am happy with a small amount of grey matter in the morning as my breed is prone to this but any other colour or at other times of day I would have checked out.

Mouth - sweet smelling (!!!) humm, well, get to know the smell of your dog's breath so that if it changes you can describe it to the vet :)
Clean teeth and gums with no redness of gums

Feet - check for grass seeds, keep toenails trimmed and hair of long haired dog.  Check between toes top and bottom.

Groom your dog regularly and use your hands as well and get to know the map of your dog's body - where it has lumps and bumps so that if anything new appears you will know within 48 hours at the most.

Make a note of how much your dog drinks, eats, weighs, sleeps and exercises.  Amount and texture/colour/smell of output.  There are certain times when a dog has an upset stomach that you know by the smell it will probably be all over the walls as well as floor

i take my lad as and when he needs to go for any reason.i do take him every 6 months for a general check up on weight etc and then the yearly booster.it would depend on the breed as some are more pron to problems than others but you would get to know whats normal regarding your own dog and when they are unwell.
i think it depends on how good you are at checking them over and knowing whats ok and what isn't.if you check the dog over and find some thing your not sure about i would consult the vet to be on the safe side.
hope it helps

Think it depends how confident you are but would suggest a visit about 2 days after you get the pup home, then the injections and then ever time you go to have a booster of what ever you choose to do or perhaps every couple of years if you are not boosting at all.

I treat my vet like my doctor, I never take my dogs unless there is something to be done or I have reason to believe they have a problem.

Right from day one I get them use to "Standing for Examination"

I start at the front and check eyes: not bloodshot or cloudy. Nice and bright without too much matter or wet tears. (Some dogs seem to generate more tears than others but you soon get to know what is normal for each individual dog)

Ears: clean and not red. I also sniff them, they should smell "Clean". Believe me, you will know when they smell wrong!!

Teeth: Nothing bad! Gums not red. No tarter.

Feet: Check claws and if necessary trim. It's easy to trim if done regularly but if they get out of hand its hard work!

Lastly: I run my hands all over, feeling for any lumps, scratches or cuts. Burrs or thorns in the coat and of course Fleas.

As a puppy I do this two or three times a week. I don't expect to find anything but its good training for later. Later in life it is a weekly event, carried out after a day in the field working or training. The whole thing only take two or three minutes but is well worth it.

Best wishes, John