What can People Legally Immigrate into the U.S

What can People Legally Immigrate into the U.S.?
Does it Need Reform?
What are the ways that people can immigrate to the U.S. legally?
How many people immigrated into the U.S. annually over the last few years?
Are the numbers going up or down? Is this helping or hurting our unemployment problem?
Do you think we should reform our immigration policies?
If so, how should we do that? Make it harder to get in, or easier?