When you start a google group the first thing you need to do is experiment with it to see how things work and why.  Then you see what things do and how they react with your members and you as the owner as well. 

It is never a good thing to open any group and invite members to it until you have this sorted out.
Yes you are going to need 2 email addresses to do this with. You can ask a friend to help you out but in the end you have to rely on them telling you what happens accurately and understanding whats going on as well.  It is always best for an owner of any group to have a membership with at least 2 different email companies that also provide you free use all and anytime as
well. So that when or if you change your ISP (internet service provider) you do not lose access to your group.  Also some providers limit the amount of eamil you can receive within  a specific time frame so this eliminates that problem as well.

example google or yahoo or hotmail
Depending on what your email address is you may or may not receive all notices from that group expecially in google groups in full instead you might receive them as an attachment which many of us do not wish to open and in some cases are blocked.
If you do not have a "commonly known" email address then the emails.
may be redirected to bulk or spam folder or totally not received.
If you have a gmail account many of the accounts for the past year(2007) will not show what the message is about and you will have to go to the
group site to find out what it was about.
Therefore you are wiser to have a yahoo account to use as an owner as yahoo delievers the total message in full so you know right away if
its a message pending  or a member pending request.
But that also all depends on how you set the group up.
You have to go to the section of options in google group called "Group Settings"  and enter each tab in here and make sure each one is set up the way
you want YOUR group to be operated.
If you do not put all members on moderation you are not going to know if they posted or not until after they have posted and google has sent
the posting out in either individual emails or abridged or daily digest.
I seriously recommend all members be set at or advised to use "daily digest" and I seriously believe that no owner should ever set a members email preference up to anything but "Daily Digest" otherwise you will find
that some members will leave your group due to just the amount of emails they receive. Some will "think" it is spam and mark it as such and then likely never see anymore from your group and might cause a problem for the actual group. (could be that the group is marked as spam and others end up getting their messages in their bulk or spam box.) Some have a limited amount of email they they can receive.  Some have slow dialup and it could affect how long it takes them to access their email accounts.  Daily digest is one per day max in most groups and covers each posting totally.  It is also way easier for non techy people to follow what is happening.

Its totally an owners choice on how much time they wish to invest in their group as to whether they choose moderation or not
1.Some feel moderation is too much work and would rather go through
each posting and delete the offensive or spamming ones individually later after each member has already received the offensive material.
2. Some feel that moderating each posting and members is way less work and worry and to be able to Stop the offensive matter or spam before any member must
deal with it.
I tend to be one of the latter and find its way less time consuming than the first method.

The rest is pretty much self explanitory.
If you keep one of you email addresses as just a member you will always know what it is that your members are seeing as well.
Then if there are problems you can see it first hand and deal with it.

I have likely missed a few things here so just ask if there is
anything else needed to be covered.