Check this out:
http://www.kreativsounds.com/reason-...deo-tutorials/
"Part 2" describes recording...
(Video shows Reason 4 but it works the same way in version 5)
There are many ways to make stuff show up in the sequencer. If you have made a nice drum pattern in say ReDrum, you can right-click on the device and choose "copy pattern to track". Now, that pattern will show up on a Redrum notelane in the main sequencer window.
You can also use the pencil tool: Add a device (like a Thor) to the rack and then use the pencil tool to draw a couple of bars in the notelane of the Thor in the sequencer. Then double-click the part you just "painted" to open it up for editing. You'll see a piano-roll and you can add sound with the pencil tool to manually "paint" a melody...