I got a sprint 642R router that i want to use my new service.
Thing is i am unsure what configuration options to set to get it to
work with my ppoe connection.
I have about 8 ip address and i want it to automaticly assign it to
different devices and login.

You mention that you have 8 IPs you can use and are also referencing
using PPPoE. Most ISPs use PPPoE to Dynamicly assign IPs from a large
"pool" of IPs. But when you are given 8 IPs those are usually staticly
assinged and do not use PPPoE but it is becoming a more common
practice.

I will see if I can help you out here with a quick answer but I might
suggest you also browse the forums for your ISP at www.dslreports.com
it is a very friendly community and alot of the users there are very
helpful.

If you have 8 IPs assigned from you ISP then you could use the
following and most common configuration. I will use "local" IPs for an
example rather than "public" IPs.

If your IP block assigned is:
192.168.1.1 to 192.168.1.8
You will not be able to assign the first and last IPs as they define
the range. (192.168.1.1 and 192.168.1.8)
The Second Ip (192.168.1.2) in the range would normally be assigned to
a router or some other device. A router is the most common
configuration.
The you would assign each of the next IPs to individual computers up
to 5.
192.168.1.3 ..4 ..5 ..6 and ..7.

If you are using a PPPoE connection that dynamicly assigns an IP you
can find information here for your specific router:

ftp://ftp.zyxel.com/p642r/document/p642r_v1_UsersGuide.pdf

The ZyXeL site is almost always slow so give it time for the page to
load.
It is actually a Zyxel router and they are usually fairly user
friendly to setup.

You will need to enter your username and password for the PPPoE
conneciton, and if running multiple computers through a hub then you
will need to setup an internal Ip scheme as well.  It all really
depends on how you want to use you rhome network. If you just want to
connect to the internet then 1 public Ip to the router and internal
private IPs on your computer is fine but if you are running mail/web
servers or need to connect to a PC at that location from another
location then multiple public IPs are preferable.

If you leave a little more info about your service or what you want
your home network to do I may be able to help more.

(FYI I'm not an official answer person) ;) Just helping out.