情報 is the word for "information" in general. In the given example sentences, 情報 is the only word that can be used (another option is 詳細 "details").
お知らせ is more like "notification" or "announcement" (of an upcoming event). You should remember this as a lexicalized word that is almost always used with お, even though some dictionaries may not have a dedicated entry for this. (A few writers may drop お in serious sentences, but it's rare.)
XYZ Department Store Closure Notice
At the end of the concert, there was an announcement of the release of a new song.
知らせ (without お) is "news" or "report" of some important event that has already happened. There are cases where "information" is a valid translation, but it's far from the primary translation of this word. Besides, this is a stilted word used mainly in formal greetings, essays and such. 知らせ also means "sign; omen" in a few set phrases.
I rushed to the hospital upon hearing the news that A was in critical condition.
We look forward to hearing good news from you.
So パーティーの情報 refers to the information (the hour, the place, etc.) about the party. パーティーのお知らせ refers to the announcement (or the invitation) itself. パーティーの知らせ sounds like an odd expression to me (but if someone really said this, it should refer to the same thing as パーティーのお知らせ). If you thought you heard 知らせ "in daily life" in such a context, I suspect you have misheard something or seen some weird misspelling.