at this age you can't expect them to respond the way you'd expect an older child or adult too. Distraction is your friend. Try to use a word other than 'no' too...for example...your baby boy is turning the nobs on daddy's prized stereo system..you say "baby, hands away!" he won't listen or take them away but he may acknowledge you at best!!! so you physically remove him and take him to a place he's allowed....next time he's at the spot you told him no...you say...."mummy said no touching...hands away" use a firm tone and shake your head and remove him again. won't take long till he gets it. they understand 'no' but it's better to tell them what you want..ie hands away, no touching.
to praise him...praise the behaviour, try not to use 'good boy', instead...good walking, good playing, good eating, good sleeping...lots of claps big smiles and touching (kisses and cuddles) when he does what you see as good behaviour.
smile consistency is the key. decide on the house rules and stick to them. no confusion and hubby on board and soon enough he'll know the no go areas.