We recently rehomed a BAssett Hound (2 months ago) - he is nearly 3 yrs.  We already have a dog,lab x - they get on very well and have become great mates.  Im many ways he has settled quite well but occasionally he can become quite aggressive, growling and jumping up which as we have two children (6 & 8 yrs) is causing us concern.  We have one sofa in the lounge which the dogs are allowed on, sometimes he will sneak on the good sofa and when asked to move (nicley) he starts growling, sometimes he will move begrudgingly but the other night jumped off and came up to me growling and barking which is quite unnerving.  He then swiped some food off the table the next day and again when told off started to get nasty, although in the end he went up to my husband and nestled in as if to say he was sorry! One evening my daughter came downstairs crying and he jumped up and came over growling, I think he was a bit frightend.  Interestly when he is doing this growling, his tail is sometimes wagging.
We know some of his history from the previous owners, they did not have him rehomed because of aggression, said he'd never bitten anyone altho there were no young children there,
but did have a passion for sitting on chairs and sofas so he was only allowed in their conservatory!!  I've spoken to my vet about a session with behaviourist although this seems very expensive, another option is to get him castrated (our lab has been) to see if this curbs it.
As a last resort we are considering whether he should be rehomed as the aggression does worry us when we have young children around. 
Any ideas suggestions welcome

The food stealing is normal and hounds are very good at it, the growling may be that he has not learned your house rules yet, would withdraw all privilege from both dogs and try to start again as if he were a puppy, if he does not know how to behave he wont. If you are concerned that he really is a threat to the children then perhaps you should ask for help from an outsider or perhaps training classes may be enough. Would try not to be physical with him but he needs to learn the house rules.

Hi
We have a bassett x. He is quite a character. Are you sure he is growling and not just grumbling? Our boy George like to sit in chairs but he knows he isn't allowed. When I try to remove him he makes sounds that are like growl but they are really just complaints. Like yours, he very begrudgingly moves. It might just be that you are all getting to know each other.
I hope you sort him out cos Bassetts are lovely dogs with super characters and a great sense of humour. :)

You might like to try attaching a short length of line (washing line or similar) to his collar so you can use this to manouvre him off the settee without getting too confrontational.  It would perhaps be worth getting a vet to check him out (particularly his back) incase there is some pain causing him to grumble.