I started riding again after a 13 year or so break about 3 weeks ago,because my ever reliable landrover broke down again. 
The weather was lovely, so rather than using my wife's ford focus, I decided to dig out an Apollo phase mtb I bought on a whim but had never actually used in 
Halfords last year. 
Bearing in mind this bike weighs a smidgen less than the titanic, my first ride was from home to my work office 
It was a staggering 0.9 miles, which I completed in 5.37, including stopping for traffic lights.  My average speed was 10.1 mph, which wasnt to shabby. 
My next few rides were from home to work, a 1.4 mile trip, which took around 8 minutes, again including traffic stops.  My average speed seemed consistent around 10mph
I then did a 4.3 mile trip, with a 5kg bottle of power steering fluid in my rucksack for the car! I did this in 26 minutes and averaged 9.6 mph. It was a mix of road and canal tow path, I was well chuffed though, after only 3 days riding. 
I'd gotten the bug again, and quickly realised the Apollo just wasnt cutting it, so I bought an old but well spec'd carerra zelos mtb. It weighs about 13kg, so considerably lighter than the Apollo.
 My first ride on it was a 10 miler down the canal towpath and I was averaging around 11.5 mph 
From then on I've increased my distance each time to 13.6 miles averaging 12.2mph
Then 16 miles but my phone turned off, so I lost the GPS data
My next ride was only 12.4 miles, but for the first time I actually did some proper hills, max elevation was 387ft up 381 down.  Not much for some, but for me it was like conquering Everest!  I even averaged 12.6 mph, probably because of the 25mph descent! 
My last ride which was on Friday was only 11.2 miles, but I wasn't feeling great, it also involved a fair bit of offroad, still averaged 10.3 mph though.
I'm now on the look out for a road bike so I can increase my distances and averages, and just save the mtb for proper off road tracks rather than fitness rides.
Since I started riding on the 15 July my total distance is 80 miles and duration is 7 hours 31 minutes. 
Plus I've gone from 13 stone to 11st 12lbs which I'm very pleased with! 
Loving riding again and can't wait to get out every time I get home from work.. Sucks today as I seem to have come with something and have no energy whatsoever, so I'm in bed looking on 
eBay and forums for a road bike to buy! 
If anyone wants to see my data, I'm now using garmin connect because I've just bought an edge 800, but I started with runtastic on the iPhone, which I do still use too, but the garmin seems more accurate. 
http://www.runtastic.com/en/users/tom-radford-2
http://connect.garmin.com/profile/tcr4x4