The first page: What crosses the line?

Almost nothing is "taboo," especially not in the realm of self-injury/suicide. You can go into as little or as MUCH detail as you want. A gritty first page will definitely draw some in, and those who are offended by it probably shouldn't be reading a book that starts with a suicide. On that note, it might help to look at the rest of your MS - does a detailed telling of a suicide fit the rest of your writing, or would it be out of place and set wrong expectations for the story.

You can do as much as you want really, but one word of caution. Violence usually isn't as compelling as we think it is for readers. They see it all the time with news and TV. So if starting with something violent, don;t forget the emotional component as well, as the person is what is more likely to grab a reader's attention than a tragic act.

Peachiemkey had some great points. In my humble opinion, an opening of a funeral sounds cliche'. We see it in movies/TV shows frequently then it goes into flashbacks to bring viewers up to that point.

I'm intrigued for an opening chapter from the gal's POV. Is she scared? Committed? Resolved? Defeated? How does her body react to her emotions? Does she reflect on the process of getting to this point? To the pain of slitting her wrists? Is she fascinated once she gets beyond the pain to watch her blood ooze/spurt? What are her thoughts as she begins to get cold/lose consciousness? Does she regret her actions once she's beyond the point of no return? Sorry, my mind's running with things that could be fascinating. Could be a powerful chapter.

Again, peachiemkey made an excellent point about would the first chapter's writing match the rest of the book. Good luck!

What's the most bizarre place you can think of for your protag to be dealing with the suicide? (that fits the story of course). Contradictions are often good beginnings because they challenge the reader's perceptions right away and intrigues them.

Just from a writing standpoint, how important is this suicide to the story? Which details are especially relevant? Was it a knife or a razorblade? Does it matter? Use as much detail as is necessary to let the scene fulfill its purpose.