Some excellent advice here!
I am a mere “hobbiest” photographer, I took a few classes in college, but am by no means an expert. However, I have taken rolls and rolls nad rolls of film on my travels, (particularly Yosemite and the Redwoods!)
My favorites: Kodachrome 64 for slide film - or the slower 25 ASA (or is it 24?) slide film from Kodak. Sure, it’s slow, but the color saturation is fabulous, and when you are taking pictures in the sun, you don’t need super-fast film. I also have had good results from Fuji’s Velvia slide film. It is really gorgeous, great colors. Actually, Velvia is better, but more expensive. And I’m cheap. But get it as much as your budget allows.
My favorite print film is good ol’ Kodak Gold ASA 100. Fuji is also good.
I would like to stress here, get the slowest film you can without having to use too slow of a shutter speed, etc. I find that on a bright day, I can get a rather high shutter speed and not use too open of an aperture (sp?) even with ASA 100 or lower. The color saturation and grain on faster films (like ASA 400) are not very good, not as good as ASA 100 or lower. Only use ASA 400+ film for low-light situations. For one thing, ASA 400+ film is more expensive, why waste it on well-lit settings where you don’t even need it? Save it for shooting in the evening, etc. If you are unsure what lighting setting you will be experiencing at all times, throw in a few rolls of ASA 200 film. Not too fast, not too slow.
Also, as bda suggests, “bracket” your exposures. I do this trick all the time, learned it from my dad (who was a"purist" who always used a hand-held light meter, but I digress…) Anyway, I usually take three exposures for each picture, which burns up the film, but I always get one exposure that pleases me. Bracketing is when you change the setting - on up, one down, whatever, from what the light meter tells you. For instance, if the light meter wants you to have a shutter speed of 250, also do one at 500, and maybe one at 125. (Or, you might want to change the aperture settings instead. Whichever - I’ll bet bda could be more specific with details.) I always find that my pictures are overexposed when I use my camera’s default light meter settings, so I bracket by underexposing one, and then two, stops. I always get at least one picture that pleases me using this technique. (This “overexposed” problem seems more noticable when I am shooting in bright sun, I thought I’d mention that.) I use an old Olympus OM 10, but I also noticed this overexposure problem with my dad’s old Vivitar SLR 35 mm camera also.
Well, probably giving you more info than you asked for, so I’ll end this now.