While common sense cleaning practices will keep you safe, I feel the need to say I don't think or worry about salmonella. I give my snakes kisses all the time, have done it for going on three years with no ill effects that I can recall. Sure I could be a lot more careful, but truthfully I don't worry overmuch about it. I figure with all the stuff you see in the news about contaminated food and such, if I'm going to get it, it's a lot more likely I'll get it from food than from one of my snakes.
Now, this does not mean I make it a habit to lick my snakes under any circumstances. And if I clean a tub where one made a mess, that snake gets a quick wipe down with unscented non antibacterial baby wipes and the kisses get held off until another day.
As far as surfaces go, I wouldn't follow your snake around with a can of Lysol, but I'd want to wipe the table off before I sat down to eat where the snake was laying.
Bottom line, use your own good judgment, and you should be fine.
Gale