Question : Setting up multiple VLANs without layer 3 switching

I am looking for some outline advice on how best to set up a multi business network (everyone sharing the same infrastructure) and still keep the data segregated from each other. It is for use in some serviced offices.
 
The users would have access to a shared internet connection, and later down the line a shared print service (comprising of a server and printer attached). The switch we have is a NetGear GS724TS Smart switch which can vlan tag but not much else. There is no budget for any other kit.
 
One option could be to vlan each business, put the gateway on the management port on the switch and then setup a dhcp server on each Vlan to dish out the IPs. Would the DHCP scope have to be in the same subnet as the gateway because there is no routing happening over the switch? This model could mean that each dhcp scope would need to be unique but because its VLANed the traffic shouldnt be accessible from another vlan. E.g Gateway is on 192.168.0.1 and VLAN 1 is 192.168.0.10 to 192.168.0.20 VLAN 2 could be 192.168.0.30-40 etc.
 
Another option could be to do the above but have fixed IPs. Therefore negating the need for an individual dhcp server on each vlan (so saving money as you wouldnt need windows server 2003 license or other equivalent). This has the added complication of my maintaining an IP list per tenant and them manually fixing their own IP, not a very smooth system.
 
Another option could be to install a cable router as each new tenants gateway. That would then point to the main Gateway. All routing and DHCP would therefore be done by the tenants router. This option could be expensive and cause more problems down the line as Im not sure it can be expanded for group printing. This could also have a high admin overhead.
 
I think Option 1 is the way to go. I also think it could be expanded to have the printserver included in the management vlan that the other vlans point to which should allow group printing. Is there an alternative to server 2003 for the DHCP server as it could get expensive for the licensing, perhaps a linux box?

Do any of my ramblings make sense?

Answer : Setting up multiple VLANs without layer 3 switching

Ok first of all if you need any croos over of the traffic (and you will if you want to use the same internet connection and same printserver) you will need at least one router.

however as this is the only place that traffic can move between vlans it is qquite stright forward to limit how the traffic moves.

I would suggest you set up a seperate network for the printserver, which each of the seperate networks can then connect in to. You would also sit the central dhcp server up on this "service network" and as ngravatt suggested use DHCP helpers so that each VLAN can use the single dhpc server.

This is very simple to do you simple create a pool of addresses for each of the networks.
each VLAN has a port on the router connected to i and this port is assigend the address that will act as the default gate way. This port is also told the IP address of the dhcp server.

When a device in the vlan sends out a dhcp request this port will pick it up (DHCP are broadcast) tag it with its own network details and forward it to the DHCP server. this will replay with a vaild address if one of its address pools match the details of the network details.

You relly need a fire wall to control the access between vlans, although you can do ti with access lists.

so say you have 4 vlans

VLAN a = company A
VALN B = comapny B
VLAN c = comapny C
VLAN D = service netwrok (DHCP/DNS/Printer)

your rules would be

A, B and C can't directly talk to each other, no routing takes place

A, B or C can talk to VLAN D but only with requests for DHCP, DNS, and print requests.

VLAN D can't talk to any one only respond to requests (so it can be ues to jump between vlans)

now each VLAN is secure from each other but can use central managed services.