Calling all weight lifters!

So I just started using the free weights at the gym...I've always just liked using the resistance machines and weight machines. The day after I used the free weights I felt so good.. It was such a good soreness!

So my question is...how many reps should I start with and should I start with the heaviest weight I can lift or the lightest?
I am going to search exercises I can do with them but need to know where to begin!

TIA! :)