Question : Data Back Up proceedures\processes

HI I need some advice on implementing a data backup proceedure\process.
In our firm we have  4 windows 2003 servers, two of them are used for data storage.  We have recently purchased two NAS server, one is used to mirror the other over our LES circuit to a remote office whic gives us our remote backup of live data but doesnt give any time based restore options.

Currently we use windows backup  to back up the data on the windows servers we then maunally copy the backup files created to the NAS server. At the same time we are moving the data ffrom the Servers to the NAS server which will eventually be the main data storage area.   Currently we have no futher backup solution except for the primary NAS replicating to the Backup NAS.

I've looked into Backup solutions such as Acronis, Arcserve etc, but as i'm new to implementaing a backup proceedure, I would like some advice from those who know. So I guess my questions are as follows.

1. should I continue using Windows backup for the server data. ?
2. would it be better to move all the data to the NAS and then create backups of this ?( baring in mind the backup NAS provides a live backup, shceduled to replicate every night)
3. Would it be a good idea to move the data to the NAS, then create the data backups (of the NAS) on the servers , then move this to external media for off site ?
4. What is a good solution for off site backups ?  I have looked into tapes drives but these seem very expensive, are External hard hard drives a good idea ???
5. At the moment we are rely in on Windows backup to be able to create data restores, but i'm not sure if this is the best solution. Can I use this to create backups of the NAS onto the W2003 server ?????
5. Can anyone provide a a good source (websites) with info for developing an effective backup proceedure ?
6. If you have a better suggestion for our scenario I would be most grateful. I will be funding implement a good solution but I want to make sure its the right one. Preferably one that can reduce human intervention and time overhead.

Many Thx.

Answer : Data Back Up proceedures\processes

Hi,

Create one test user on  exchange server. Try configuring test exchange account in outlook 2007 and at the same time check the connection being establish or timewait on the client side along with port numbers through command line mentioned below.

netstat -n | find "enter you exchange server IP" in case if the connection is being establish on the different port which is not allowed under your firewall then you also have to allow that port on the server firewall and check if it works.

Meanwhile I would also suggest you to configure test exchange user account with using exchange server IP address and check if it is working for you.