Vlan trunk ports

Ok, so I have to admit I'm a bit of a noob with vlans. I've never really needed to separate my network until now.

I have 3 vlans with unaware devices on 2 old 26 port dlink switches (des-3526). There's also a router providing internet access (old sonicwall)

Yes... I need to upgrade ;)

To make a long story short, I'm trying to use ports 25 and 26 on the switches to uplink from the router to the first switch, and the first switch to the second. Vlan ports are untagged, and the uplink ports on each vlan are tagged. Egress is selected for all ports included in the vlan, with forbidden for ports that are not. Vlans with matching id's are created on all devices.

Ports 25 and 26 aren't accessible from any of the vlans, though. The manual isn't much help - dlink seems to use some odd terminology. I'd normally call ports 25 and 26 a vlan trunk, but "trunk" to dlink seems to refer to link aggregation...

I can't help but think I'm missing something incredibly simple here... Any clues for me as to where this noob should start?