Dogs 101 is a good show to watch about different dog breeds - you may be able to catch some of the shows on youtube - they used to show it on Animal Planet but not sure if it's on at the moment.
Anyway, some of the things I've discovered through having my own dogs and watching shows like that are things like:
- Greyhounds make excellent pets, and contrary to popular belief don't require a lot of exercise (they run and run for about half an hour and then sleep for 2 days........whippets are similar). Greyhounds aren't particularly good guard dogs though, they're too dim to notice anything unusual going on

- Terriers are often purchased by people who think 'small dog, less exercise' and they couldn't be more wrong. You take a terrier on a 5 mile walk and get home, then 10 mins later it'll want to go out again - they are yappy though and likely to notice anyone within a mile radius of your house

- Dobermans, Rotties and Pitbulls are lovely dogs given a bad press because of people training them up for all the wrong reasons. However, I have to say that with kids, probably not the best idea because if a dog like that does suddenly bite then it's going to do damage. Best for older people I always think.
- Chow Chows are apparently not good with kids (they're quick tempered), likewise Chihuahuas, Yorkshire Terriers and surprisingly Dalmations. The little dogs have Napoleon complexes and Dalmations can be skittish.
- German Shepherds are supposed to be good, Labradors (or doodles), Wowzers (Schnauzer/Westie crosses), Retrievers, Boxers, pugs.
If you're getting the dog when you get back to Europe you may even be able to get one from a shelter. A friend got a Lurcher pup from a shelter and it was a lovely dog - very lovable but a 'sight dog' breed so slightly dopey (sight dogs seem to get themselves into all kinds of trouble, always falling into rivers and down holes etc, but they're very nice natured dogs).