Your vet or pet shop can advise you on this. Brush the coat up first, against the natural direction of the coat hair. This will ensure that you brush out any debris and that you are brushing the coat right down to the base, rather than just smoothing down the top layers. This is particularly important with breeds that have a double coat, that is a dense undercoat under a longer coarser top coat, so that you avoid matting and tangles. Brushes are best for this.
Combs are usually best on shorter, more open coats.
A grooming aid can be used to help remove tangles and to add body and control to longer coats. Simply spray grooming aid on while the coat is brushed up, and then brush through the coat, after allowing a minute for it to dry. You will then have a smooth, static free and manageable coat. Bath time is a matter of personal preference, both yours and your dog's. In other words, you should bath your dog as often as you feel it needs it, or, if its preference is for messy activities, as often as you feel you need him bathed.