Google has a feast of information on this, try asking 'migrating from Access to sql server'
Your SQL Server also comes with help. Look up using DTS to do the transfer, it has a transfer from access fearure which is very easy to use. Once tranfered check your primary keys, these can get lost in the transfer.
Access is web based, not sure what you mean here. SQL Server is an enterprize data store that will give you scaleability (amoung other things) over Access.
Wind is your friend