if you do a search i am sure theres a detailed post about selection. anyway heres what happened on mine.
Introduction then medical - a lot of waiting about, doc checks out your joints (by getting to you to bend and squat etc), eyesight, blood pressure, Fat %, BMI. the usual stuff but in greater detail. then its off to the hearing test, very easy, sit in a booth and press when you hear the sounds. Trip to the bar and then bed. Strenght tests- 3 exercises, one where you kind of get strapped in standing up and have to lean back as hard as you can for a certain amount of time, one is where your lifting weights to head height or above, and sorry i cant rememeber the 3rd machine?!!

Then we had the jerry can carry, you hold 2 jerry cans and have to do a a kind of bleep test in line with the PTI, then its on to pull ups, jump up to wooden beam and do as many as you can, i only managed to do 10 but in my final interview he said thats average at this stage. be warned though they do knock some off if you dont go right down whilst doing them. Then theres the 1.5 mile run, you get taken on a little cheeky warm up first so try running more than 1.5 miles whilst training, i did but some people on the RSC didnt and struggled when it came to the run?! If your RSC is up near Edinbrough then its quite a nice run haha down a country path along a river lol, just put in max effort. Then warm down - do as the instructor says asap, some guys in our group were messing about and we had to do bowt 30-40 mins extra running where he just kept shouting right to the tree, sprint to the goal post etc and leopard crawling. After that we did the grenade test, (NOT LIVE

). quite fun, scramble through a tunnel and throw a dead grenade in to artifical bunker. Finally its off for a shower and changed into a suit for final interview. In between the physical you have an ice breaker presentation where you speak about yourself etc in front of the group, a very brief lesson on the weapons (which you have a test on the next day) and if your trade requires it a maths test.
hope that helped mate and good luck.
Ps, mine was in may and got offered basic training in november