One of the most important things you have to realize about photographing meteor showers is that I would say over 50% of it is luck and how long you're willing to sit around doing nothing. This is because meteor shower strength is notoriously difficult to predict, and you generally have less than 1 meteor per minute. Plus, they can really appear pretty much anywhere in the sky, it's just that if you trace them all back (draw a long line through all of them) they will emanate from a single location (the radiant) which is how they're named - in this case, appearing to come from Eta Aquarius (I think that's the 4th-brightest star in the constellation Aquarius).
With that in mind, there are a few things you can do, with two main approaches.
The first approach is, "Lots of short photos." This is where you use a large aperture and take photographs more often, hoping that you'll get a meteor in the exposure. You have to take them more often because with a larger aperture, sky glow will become an issue more quickly, and you'll just get an orange-red glow over the entire picture.
The second approach is, "Fewer longer photos." This is the opposite, where you have a smaller aperture, meaning you may miss fainter meteors (though they're usually quite bright in comparison with most stars), but you don't have to weed through so many pictures of a blank star field.
As for lens, you want the widest-angle you have because the meteors, as I said before, can really be anywhere in the sky, they just appear to emanate from the radiant if you draw a line back, tracing their path. You could pick a spot near the radiant and just stay there, hoping that the next meteor chooses that direction and that location to hit Earth's atmosphere.
I don't really mean to discourage folks (as I think the tone of this reply is fairly negative), as watching meteor showers can be a lot of fun. But, photographing them is much more difficult -- your eyes have a near-180° field of view, but an 18mm lens on a 1.6x crop body offers only a 64° horizontal field, and so your likelihood of photographing the meteor is much less likely than just observing it with your eyes.