Well I am ready to do the first test roll in my Century and I have always used Tmax-100 with my 35mm photos and loved the quality. I am looking for a very fine grain, very sharp, and great contrast from a B&W 100 or lower 120 film. What do you guys like to use? I will be doing my test roll out doors on a good sunny day.

ISO 400 for camera testing as very minor light leaks will show up on the faster film better than on slow film.

ISO 400 also allows for faster shutter speeds for hand holding.

As long-time readers here will know (uh-oh, here he goes again!), I've been using only Ilford XP2 Super b/w chromogenic film, at E.I.100 (nominal is 400). It scans beautifully, especially if "overexposed" two stops to build up a bit more density in the neg, and it's developed in C-41 (color negative) chemistry, which eliminates the need for wet developing, as with conventional b/w. Almost any camera store with a lab can handle C-41. Try it, you may like it! (BTW, it's also cheaper than Kodak's version---400CN I think it's called, but it's been a long time since I shot Kodak film of any kind, and you may not be able to get it much longer anyway! I buy film by mail from B&H Photo in NYC; if I order before 4:00 p.m., UPS has it at my front door in Allentown the next day.)

I like Tmax 100 the best for most of my shoting

BUT for testing do like he said ""ISO 400 for camera testing as
very minor light leaks will show up on the faster""

looks like a good idea to me!!!

Ok I got a roll of ILFORD Delta Pro 400 as test roll and was going to use the sunny day rule, but my lens only shoots at the fastest 200 speed. If I set the shutter at 200 would that mean I have the aperture set at f22? Also I have a Red (A) filter I would like to try out on a few shots and I know that it calls for +3 in stops... I am amusing that if the correct stop is f22, plus 3 would be f8?

yes sunny 16 with asa 400 is 400 @ f16 or 200 @ 22
And plus 3 would be f8 yes

Just a note: Except for when the sun is exceptionally bright, I've found that where I live (north of the border, in Alberta, Canada), sunny 11 is more accurate than sunny 16 -- according to my light meter, anyway.