If any of you lacks wisdom, he should ask God who gives generously to all without finding fault, and it will be given to him.And that, kids, is why you never take verses out of context!
Instead, let's look at what James is talking about, and then look at several possible meanings and pick the ones that coincide with the rest of scripture.
In the preceding verses, James is telling us that trails can produce maturity and completeness in us, so that we move closer to "not lacking anything" (i.e., in the way of spiritual and mental tools, skills and habits used to glorify God in this life). He follows that up with verse five. I think this verse does not only apply to those who are going through trails, although that may be a moot point because all Christians will at some point.
The point is that if you recognize you lack wisdom enough to ask for it from God, you are already practicing humility and the beginnings of wisdom. The passage does not specify how God will dole out this wisdom to you; I have seen a new believer pray for wisdom then go study the word and take pages of Holy Spirit driven notes on how to apply the words of the writer to our lives today, without compromise. This promise is connected to the one on trials, though, so don't be surprised if the gift wisdom is wrapped in the paper of hardship.
Here's my take on the "without finding fault" phrase. We can say right off the bat that this must be consistent with the rest of the Bible, so it doesn't mean that God doesn't find fault with anybody. Additionally, that would taking it out of context, even out of the very sentence it's in. God does not find fault in the act of asking for wisdom; instead his response is to give wisdom generously.
And we can't wrap up this section without the very convicting tag, James 1:6-8:
But when he asks, he must believe and not doubt, because he who doubts is like a wave of the sea, blown and tossed by the wind. That man should not think he will receive anything from the Lord; he is a double-minded man, unstable in all he does.If you ask God for something that he has guaranteed in his Word that He will give and then you doubt that promise, you have just doubted that God is who He says He is. You have told the one true God, omniscient and omnipotent, that you aren't completely sure He can deliver on a promise. And because God is not obliged to you in any way, He won't deliver. If this bothers you, ask yourself whom is here for whom; then read Psalm 19 and Job 38 through 42. Actually, just read all of Job.
And if you read all that and still think that's harsh, keep reading the Bible, then read this book. Long story short, we are here to glorify God and that turns out to be the best, most joyful and most satisfying thing we can do... because it is what we as humans were meant to do.