If you havnt got the bike already have a look on
eBay for a Chris Boardman Hybrid. These come from
Halfords but are pretty nice bikes. I managed to pick up a Boardman Hybrid Comp 2010 for £175 back in october. Its got 700x28c wheels, 18 gears and is a very nice ride.
I use it to commute the 20 mile round trip to work and back a few days a week. Its all on the roads and take me about 50 minutes each way.
As for showering etc, we dont have showers where I work and believe me when im on the bike i SWEAT!
But ive found that having a shower in the morning and then just using baby wipes and deodrant at work does the job. Aparantly clean sweat doesnt smell so im ok.
On the return journey I have a quick shower when at home...