I watched the end of the anime of Death Note. Was it said in the manga that L's name is Lawliet? Because it was never mentioned in the anime. And, how exactly did Mikami die? All of a sudden gallons of blood gushed out of him. Random...
His full name is L(first name) Lawliet(last name). So his first name is just the letter,'L'. It's really clever once you think about it.
Well, in the anime it showed Rem looking over L's head, and it said "L. Lawliet" so no, his name isn't Lawliet, that would be his last name. Mikami died from committing suicide with a pen. That's why he was gushing blood everywhere.
Your question isn't actually that random. I didn't know what was up with Mikami either until I looked it up.
It was revealed in Death Note: How To Read Volume 13 that his name is L Lawliet, his first name being L and last name being Lawliet.
It was also shown in L change the WorLd that he had written L Lawliet in the Death Note.
As for Mikami... I'm not sure. He just randomly started bleeding out...
L's real name was first revealed in How To Read 13 (the last manga volume, you could call it an "Death Note encyclopedia" XD) and Mikami stabbed himself to death with his pen.
I think Mikami tore off his thumb and died of blood loss. There was a short shot at him pulling and pressing his thumb, but I can't find a screen anywhere.