Besides the strop, make sure you get a quality soap, as mentioned above. Look at the recommended brands in the reviews here. Even though some of them are pricey, they do last a long time.
I don't know where you are, but in central texas lots of stores carry a brand Herban Cowboy (also sold under the name Natural Grooming or something like that). Don't buy their shaving soap! It dries out on your face right away and also makes your face dry, leading to LOTS of abrasions. I've tried both of their soaps, and they're horrible. Their boar's hair brush is pretty lame, but for $7 I guess it gets the job done. Anyway, buy a quality soap (or cream), it will make learning to use a straight a lot easier.