Let's see if I can tackle some of these. Keep in mind these are Chicago suburbs prices, but I imagine they'd be about what you'd pay too.
Steakhouse: Do you mean like a Sizzler/Ponderosa/Ryan's type thing where there's a buffet and you place an order for an entree? In that case your tip would be about 10 - 15% percent, depending on how attentive your waiter was and how much work they had to do. If they just sat you at a table and dropped off your meal, 10%. If they got your drinks and did anything extra for you like got you extra sauce, napkins, etc. it would be closer to 15%
Cafeteria: If it's a completely self serve thing where you take a tray, pay for your food, seat yourself, and get your own drinks, you don't owe anyone a tip. You should clear your own table unless someone offers to take it for you. Even if they offer to clear your table after the meal, you don't need to tip. They're probably a regular employee who's just responsible for keeping the dining area clean.
If it's an Old Country Buffet type place where there's someone coming around clearing your dishes several times during your meal, it's nice to leave $0.50 - $1 per person on the table when you leave.
Valet: At a resort or nice restaurant you would tip the valet $2 - $3 dollars when you pick your car up. Some folks are extra nice and also tip when they drop their car off, but that's really not necessary or expected.
Bellhop: A bellhop generally gets $1 per bag. If your bags are large, bulky, heavy, or require special care, it's better to give $2 per bag.
Housekeeping: Some people don't tip housekeeping, but it's pretty common and is usually expected. We usually tip $1 per person per night, plus $1 extra. So when DH and I travel together, it's $3 per night. If you're very messy, have small children, or need extra supplies, add an extra dollar or two. You should usually leave the tip every night as your housekeeper may differ from day to day.
Car Wash Attendant: Around here, the guy who dries your car after the wash gets $2 - $3 for an average size car, more for a big van or SUV.
I know it seems like a lot. It seems like I'm tipping every single person I talk to when we travel! The best thing I can tell you is to always have lots of small bills on you when you travel.
In general for us, if the person isn't behind a counter, IS wearing a uniform, and provided a service for us, they usually get tipped. If you're not sure exactly how much, $2 - $3 is usually enough to cover most small jobs.