train tickets for spain

can anyone help me? im wanting to travel through spain and portugal for four weeks at the end of the summer, and cant decide what train ticket is the best to buy. do you have to pay supplements on all of the trains? and which ones do you only get half price for? PLEASE HELP ME!!!!!

Here is the information about Interrail. You won't have to pay 50%, you only have to pay for the reservation service (about 3 euros, I think) and some other supplements. Unfortunately, in most trains you will have to pay a supplement but not 50%.

cheers for the help, but say im travelling from madrid to barcelona, do i only have to pay a supplement or does the ticket just get us money off the actual price and we have to pay the rest? is it discounted travel or free?

thanks

It's "free" but you in nearly all trains you have to pay supplements (for the bed, the reservation, etc), but it shouldn't be much.

nice one. cheers. how good is valencia? i have it on my route to travel to but haven't really found much out about it like i have with barcelona and madrid. is it a good place to visit?