DaveTrave, Backtothetop and willard speak much sense.
There has been a period of busyness for the TA (esp the trades, but even for the infanteers that are happy to deploy), but with the drawdown in Afghanistan, even with the increased reliance on Reserve Forces, the requirement to mobilise will drop right off.
I actually think it’s not a bad time to get involved; you’ll have to do ‘Phase 1’ training within your Btn / Bgde, before heading off for ‘Phase 2’ at Catterick (assuming you go Infantry). This will all take time: waiting for a training cycle to start, then bidding / getting a phase 2 slot. I’d be surprised if you were ready to / they’d want you to deploy within the next 12 – 18 months.
By that time the ‘opportunities’ available to deploy will be ever further reduced, but with the increased funding that the TA / Army Reserve is set to get, there should be some good exercises / AT / courses to get involved in.
Give it a go. Worse thing that can happen is that you don’t like it and hand your kit back. Be honest with yourself and the guys training you. If you’re NFI, tell them so, hand kit in, paperwork done and everyone is happy. If you just stop turning up and have a load of kit signed for, it gets a bit tedious, because you may well end up getting chased.
Another good resource is ARSSE. There’s loads of stuff on there and people asking similar questions to yours. Just be prepared for a slightly less friendly approach than here (the ‘banter’ is set to 11).
Edit: And what wheelz said.