Fornication is not a mistake, its a choice. Fornication does not just happen out of no where (like stubbing ones toe), there are many steps that lead to it, and if a man goes out and buys condoms, then he clearly knows that he is taking steps towards fornicating. If he sees where he is heading and chooses to go there anyways, the choice is his own, and I have no sympathy for him.
Depending on one's state of being, reading about sex may be one of the first steps towards fornication, as thought necessarily precedes choice. If the OP knows that he is likely to give in to such temptations he would be better to keep his mind from the subject entirely. "Finally, brothers and sisters, whatever is true, whatever is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable--if anything is excellent or praiseworthy--think about such things." But if he is strong in will and needs to learn something for a greater ends, then he should proceed, but always checking his motives.
