How to connect to SQL server 2008 standard edition?

Hi there,
I am a member of this forum. I am interested to learn SQL server, now i own 2008 standard edition version. Just got it downloaded from website.

I do not know anything about this. This is a main aim why joining to this forum expecting some one can walk me through steps.

Firstly, I would like to do is:
I am planning to install SQL server on primary domain controller (PDC) so that PDC server can centrallizing user account. I also plan to have an internal intranet. Once user is prompted for changing password occassionally. user only change his password once and affects to intranet and his account in AD services. at the same time having SQL server holds a sales database.

Secondly, User can access to sales database on lan and remote access from other places. How can i make this happen?

Thirdly,
Fouthly,
Fithly,

I may stop at point before getting to any further.
Can somebody give me some instruction in detail please?

Thank you