I never used (MIDI-)hardware with a DAW before but I’m interested to at least control my soft synths and effects with a hardware controller. What kind of audio interface is preferable for connecting say 2-3 MIDI devices to my laptop? Today everything works with USB, I guess? I really never got interested in this hardware stuff before so I’m a total noob concerining this stuff. 0:)
I just need some basic starting points to be clear about what I might need for the beginning.
Well, if you just want to control VSTs/AUs/whatever and/or Renoise itself, you don’t need any special “audio interface” at all (unless you own hardware with a “classic” MIDI-Port).
As you said, it’s all USB nowadays. 
Just plug in the controller, install drivers if necessary and the fun starts.
The number of devices is just limited by the number of available USB-ports and can easily be expanded with a simple cheapo USB-hub…
You’ll probably want to start off with ONE device, because you can change the instrument/fx that is controlled anytime. In addition to that, the mappings are saved in the song btw, so you’ll have individual setups for each song. Just saying this, because you mentioned 2-3 devices… 
But you CAN use more devices at the same time of course (Renoise handles up to 4 midi input devices atm)…!
I suggest that you’ll start with a multifunctional controller i.e. it has a keyboard for instruments and some knobs and faders for other functions. For example, i started with a M-Audio Oxygen 49 (you’ll maybe want to go for a Oxygen 25, as you’re running a laptop and this is more portable).
Hope this helped a bit…
EDIT: typos 
i bought the simplest possible midi-keyboard about 2 years ago throught Marktplaats (Dutch equivalent of eBay) for €20. it has just keys and nothing more, no knobs and/or faders. it’s made by some obscure brand i think, but it works, through a MIDI-USB cable. it is nice to have some knobs/faders though, so you can do more than just play notes on the keyboard. the main reason i bought it was because i wanted to get away from the rigid programming of notes, and wanted them to be somewhat more fluid and human. in the end, i’m still programming notes because i don’t know how to play the piano 
Haha, thanks for your advices, guys. I found the Oxygen 49 before and think I will get this one. Maybe Ebay has some nice offers.
Just had a look at ebay (germany), they sell it for a higher price than i paid for a new one in my favourite online store… 
Yes, you’re right. I found it for around 135€, which is nice I guess. The small Oxygen (25) is only 20-30 bucks cheaper. That’s not a hard decision then.
I can absolutely back plasmaniac up - I own a controller identical to the M-Audio Oxygen 49 (made by a cheaper company in the same factory apparently) and it’s a great starter controller. There’s a bit of lag with the keys if you plan on triggering samples from them live but the faders and knobs are perfect for midi mapping. The controller is easy to set up and certainly helped me think a little more outside the box when it comes to programming songs.
Anyone used the Akai MPK Mini? I’ve read great reviews, it’s <£100 and I’m thinking of getting one. Keys, pads, and knobs included.
A friend of mine also showed the MPK Mini to me but somehow I think the Oxygen 49 offers more value for my money. Price around 135€ (around £120).
What’s the brand name on your clone?
I really do want pads though. Can you comment on the sturdiness of the MPK? Because if it’s flimsy I will just break it in no time.