I suggest HP5+, Delta 400 (new), Fuji Neopan 400 or any of the b&w chromogenic films made for processing in C-41 color chemistry. The reason? 400 speed films are inherently lower in contrast than slower films in the ISO 100 range. Also, the higher speed films have more grain and the grain tends to smooth facial imperfections.(posted 8312 days ago)Of even greater concern is lighting. Generally speaking, for basic portraiture you want softer light, such as open shade. A classic lighting technique is simple north light. To achieve this, position your subject facing north, with no direct sunlight hitting the face. One easy solution is to place your subject against a wall that looks north. The reason this works so nicely is the wall eliminates direct sunlight while the northern sky reflects the sun, which shines from the southern half of the sky. Thus, the entire northern sky effectively becomes a huge reflector, providing full, even lighting. North light is also a very sharp light, revealing great detail, but without the harshness of direct sunlight. One final note about choosing your location: the northern sky should be as open as possible, unbroken by large trees, buildings and so forth.
Obviously, north light is not the only effective light. But I strongly recommend you begin with this quality of light and learn to recognize its subtleties. It's not by accident that the great master painters had north-facing skylights in their studios.
As for fill flash, I recommend you avoid it for now. It takes considerable experience to learn to use fill flash effectively so that it looks natural. In fact, unless you have a flash you can remove from your camera and bounce from a wall of a ceiling, I suggest you do away with it altogether for portraiture. If you need fill, get yourself some sheets of white foam-core board in 1/4"x30"x40" size, and have a friend hold it up close to the model on the side you wish to fill. You should also try holding it under the model's face, parallel to the ground. Observe how this lightens dark circles under the eyes and is especially effective for softening wrinkles.
Filters? If you do all the other stuff I recommended, you probably don't need filters. With that said, however, keep in mind that a given color filter lightens the same color in your subject. Therefore, if your subject has red, blotchy skin--acne, age spots, etc.--a red (#25) or orange (O2 or #21) filter will help considerably. Some say a yellow or green filter yields richer skin tones, but I have never found them particularly useful.
Lastly, experiment a lot. Do it straight and classic, then do it again and break the "rules." The bottom line is there is never only one way to take a photograph. That is the endless joy of photography; the countless opportunities for variation are always yours for the taking.
Good luck and have fun!