Liberty

Liberty is a female character who plays a minor but yet significant role. She is commonly thought about throughout the story, beginning in the first chapter. When Danny first sees her he has an attraction to her, but his ideal relationship with her is completely off from reality. Even though she also likes him back, there relationship is rather limited.
I am unsure why Pena made Liberty how she is. She is almost the exact opposite of Danny. She speaks almost all Spanish and hardly any English(Danny cant speak any Spanish), She just came from Mexico, she has a somewhat rich father who brought her to America. The only thing that they both have in common that they like each other and are both light skinned. Maybe Pena is just trying to show Danny's desperation as a teenager to love, no matter how adverse.
The fact that Uno and Danny are very similar and Danny and Liberty are so different is unusual. Usually all the important characters are similar. Possibly Pena is trying to really show how a teenager sometimes only see some features of people and not others. I doubt this though because Danny makes it clear that it would be a difficult relationship. I think though that when Danny hears Liberty likes him, he doesn't really care. Pena's choice for her characteristics is odd, but it does add a nice spice to the story.  

Danny and Uno

Pena's two main protagonists Danny and Uno, are actually very similar. Early on the two hate each other after Danny accidentally threw a bat and hit Manny, Uno's younger brother. Uno then punched Danny in the face. This event keeps the two from knowing each other until baseball brings them back together.
The two are very similar due to there personal live, but neither seem to understand that they are. Both of them are half Mexican. Danny is of a white mother and a Mexican father, while Uno has a Mexican mother and a black father. Both characters also want to be with there fathers. Danny's father left his mom numerous years ago, while Uno's parents are divorced. The difference is that Uno's father wants him to be with him, while Danny's father has disappeared to Mexico. The two in the end both go to see there fathers. Uno moves in with his dad, while Danny only gets a chance to visit him.
I find it intriguing on how Pena connected the two in such a way. It almost makes a symbolic connection between them. The fact that they are located in the middle of a majorly Mexican area really shows how they stick together. They're hustling business which is a great success is greatly helped by their similarities which connects them together. Pena adding this connection really adds a nice touch to his novel as it shows how two people may act differently, may actually be very much alike.

Stereotypes

I found Matt de la Pena's book Mexican White Boy to be a very interesting novel. In the first few chapters though, I noticed Pena included many stereotypes. I am rather unsure about the reality of the setting. I personally have never been to a Mexican neighborhood so it may be difficult to compare it to reality.
Right off, the stereotypes are almost listed in order. All Mexicans live together, many are illegal aliens, Mexicans are rather poor, Mexicans do landscaping for white people, Mexicans drink alcohol, smoke marijuana, and swear often along with saying a lot of slang. I question Pena's intention of putting this in, but it could be concluded that he used to transfer the actuality of the slum to a reader. I still personally disagree with the extremities he went to. Everybody except for Danny seems to follow these stereotypes. I feel that Pena could have made it less stereotypical if he would have described the setting more then the people who live there.
Pena also included many unique analogies of which to describe different skin colors. I've heard racist jokes of which were similar to his analogies.  Describing skin as a chocolaty color for Mexicans seems to be a bit to extreme. He also uses similar analogies to describe other skin colors. Doing this though does provide excellent imagery to the reader to help them understand the skin color. He could have tried to use it with  more subtle usage, that would eliminate the almost rascist tone that Danny says in his thoughts.