Liteon Dh Any Good Spec?

Any good spec? - liteon dh

I think the construction of a new PC, my first attempt.

I use my computer for educational purposes such as word processing, Web sites store photos, marriage, want (in fact, many of them), they on DVD, which also store programming languages such as Visual Basic, Python, etc., to programs.

After much trawling through the internet, I am with the following specifications:

AMD Athlon 64 X2 6000 + 3.0GHz
Gigabyte GA M59SLI-S4 AM2
1 HD 250 GB Serial ATA II hard drive (OS and application storage)
2 HD: 500 GB Serial ATA II hard drive (data storage)
2 GB of RAM (1GBX2)
LiteOn DH-18A1P-18C 18x DVD ± RW
Microsoft Windows XP

The amount of watts and I am going to use the mark in the team?

What is a double-layer DVD / RW?

Which should I use?

I would welcome any comments or opinions on this specification.

Thank Windog