Since only German speakers seem to have answered so far ...
It does depend a lot on the context and the word order; it's hard to say without a specific example.
But in general, anything with 'inform you' or 'for your information' can easily sound patronizing, or at least formal and bureaucratic. So I wouldn't often use Galeazzo's 'Please be informed,' but the other suggestions in #1 are fine.
A bit friendlier, for people you know or are hoping to meet, is 'let you know':
I also wanted to let you know that I will be graduating next summer and will be available to start work anytime after June 15.
It may be better if you can avoid starting a sentence with 'For your information,' because that often sounds annoyed or insulted, sort of like 'So there!' It's a similar idiom to 'I'll have you know,' which LEO translates as 'Damit du's weißt.'
X: Hey, Y, just now wandering in? Must be nice to sleep in on a Monday.
Y: For your information, X, I've been here since 7 o'clock. I had an 8 o'clock meeting.
If the context is clearly only practical and factual, of course you can use it, but it may help to add a softening word like 'Just':
Just for your information, my flight on Thursday leaves at 4:15, so I won't be able to schedule any meetings after 1 p.m.