everyone says stretch this stretch that stretch this.
I garuntee that if you dont stretch everything(hip flexors, hammies anything) you will get an injury.
Make sure your core is strong before even thinking about deadlifting or squatting. you have enough wait on you as it is. leg raises are very good.
remember, if you stretch(take a half hour, like a yoga class, not a quick run through), you will be ok
if you do anything less then that, you will have an injury. pure and simple