I would go to this site here
, it gives a lot of information on each breed, but doesn't overload you. Small breeds like Maltese or medium-sized breeds like Miniature (NOT toy) poodles are always a safe bet. If you want a delightful, charming little dog you can't go past a miniature Schnauzer. There's so many to choose from - you'll have a lovely time deciding!
But Sharky's questions were highly relevant. Dogs are all so different there's no point suggesting a breed(s) unless you are aware of what you want from your dog and what kind of lifestyle you live and are prepared to provide for it. If you have never had a dog you need to ask yourself some very serious questions about what you have to offer. Dogs are extremely, diametrically different from cats in all ways. In their needs, their habits - everything. They require a great deal of time, for the entirety of their lives.
They are much less independent than cats and require a lot more work in terms of training (including toilet training). They are more destructive when young (and also when older if they're not adequately cared for) and require exercise on a daily basis - EVERY day - and a decent amount of exercise, no matter what the breed. They have to be a part of your family and your life, and not just left to their own devices, which is the quickest way to end up with a lonely, miserable dog. They are more expensive in terms of vet care, and most importantly, they are highly social creatures that MUST be a part of your family and be allowed to spend a large proportion of their time inside your house
They are, of course, worth every single second you put into them and spend with them. But you have to know what you're getting yourself into before you get a dog. They change your life in a number of ways, and are a huge commitment and responsibility.
Lastly, I cannot recommend highly enough to research your breeds and then try to find a rescue that suits you. There are literally millions of desperate dogs who need homes - and dogs are much harder to home once they've been abandoned than cats are. Shelters would be my first piece of advice to you as to where to start looking. It breaks my heart, and if you could give a poor, lonely, abandoned or abused dog or pup a home you'd be doing a wonderful thing.