College Loan Consolidation

[pmdvert18]

I have recently been getting loads of calls and mail from college loan corps. I am 25 yrs old and in May will have been out of college for 3 yrs. How does the loan consolidation work, what is the cost, advantages/disadvantages. From what I understand the interest rate is going up again in June so I am looking to figure this out.

Can anyone explain it to me....????