How can I configure my phone for MMS? I can not send or receive MMS-messages (containing an image) on my Nexus One phone. And I can't find many settings to set for it.

I have set an adress for APN. But there is also an IP-address, a proxieaddress and a port number that I should set.

How do I set up MMS on Nexus One?
You will need your operator's APN details (hint: ask the operator's customer service or search on Google), which you can enter through Settings &gt; Tap "Wireless &amp; network settings" &gt; Tap "Mobile networks" &gt; Tap "Access Point Names" &gt; Press "Menu Button" &gt; Tap "New APN" (eclair/2.1). 

Alternatively, many operators can send a special service message that will automatically configure the correct APN settings. You might need to contact your operator's customer service or send an SMS/text message to a special number before they send you the autoconfigure service message.