Yes, you can use both the mini-DVI port (m-DVI) and the mini-DisplayPort (m-DP) at the same time to connect to two displays.
You do not mention what in port your Dell display has, but there is a m-DVI to DVI-D adapter in the box with the Mac mini. Otherwise there are Apple and 3rd party m-DVI to VGA adapters also.
Neither the m-DVI nor the m-DP transmit audio with their video signals, so you usually need to run a separate audio cable (both analog or digital are possible) in tandem with the video cable. However, 3rd parties to the rescue. Monoprice sells a
Mini Displayport Male and USB Male/Toslink Audio to HDMI Female Converting Adapter which incorporates digital audio with the video stream and sends it over HDMI. This adapter uses a USB connection to power itself.
There is also a less expensive analog version which uses USB output for incorporating the audio with the video over HDMI;
Mini Displayport Male and USB Male Audio to HDMI Female Converting Adapter. With either of the Monoprice adapters you also use a simple HDMI to HDMI cable from the adapter to the HDTV.
Dah•veed
