Additionally, if you have loose-ball anything, consider replacing with sealed bearings. They don't have the kind of maintenance needs that loose-ball bearings do.
On the headset to take out the slop; loosen the bolts on the stem that clamp onto the top of the forks (the steer tube is what that part of the forks is called). Then you'll use the top cap bolt to snug the stem/forks/headset down together to the tension that you need--I like to have no slop and to spin easily. Others like a little more tension there. Over-tightening can damage bearings, under-tightening will leave you with slop and can damage bearings. But once you have that tension to your preference, use the stem/steertube bolts to hold it all in place.
On the tool note, however, some brands are "bucking the trend" of metric and running SAE bolts... two brands that come to mind are Snap and Form--both American-made and that likely has something to do with it. Don't use the closest metric wrench in these bolts because it's really going to suck when you've stripped out the bolt heads.
Bottom brackets; as mentioned, lots of options so make sure you get the right tool. Heather and Ian will most likely be able to tell you what you need based off of the bike and/or part you have.
When I need tools, I'll look them up on
www.ParkTool.com,
www.Pedros.com, or
www.topeak.com and then ask Heather/Ian from Performance to order me something.