Even when I was three years old, I've been told I couldn't toddle past a piano without having a wee go. I started piano lessons when I was seven. Went through some of the Royal Schools and Trinity exams but always found the pace of the lessons too slow. I started playing rock music as soon as I could - I photocopied the sheet music for Bohemian Rhapsody from a school friend and played that along with Deep Purple much to my mother's despair. When I announced I was giving up lessons she claimed that would be the end for me and music ... she was wrong! Around that stage I also started playing by ear - simple chords at first but quickly expanding when I discovered my left and right hands didn't have to agree on which key they were playing in. While at university I flatted above a chemist shop and with a piano I saved from the dump (stuck downstairs as it weighs a ton!) I entertained the staff and customers through the thin walls with my piano playing - sometimes attracting praise and applause from the other side of the wall! I also bought a second hand drum kit from a furniture store with bent and cracked cymbals at that time but restricted drumming to after shop-hours!
After uni I spent way too much money on synths and drum machines including a second-hand Korg MS-20 (which I still have) and a TR-808 drum machine (which I sold for a ridiculously small sum of money). Constrained by electronic music and MIDI at that time I was always frustrated by a lack of electric guitar and vocals. In the last few years I have fixed all that - the proud owner of a Strat and most recently (finally!!) starting to record my own singing.
My current setup has a brand spanking new M-Audio Oxygen 88 full size weighted keyboard which is a .. d r e a m .. to play into Pro Tools or GarageBand, an old Roland D-50 with dodgy keyboard, a very nice audio-technica ATM10 mic. There's also an acoustic guitar with a beautiful tone but a very severe action so I stay clear of that! I have a Mapex Jazz kit with four suspended toms, cheaper (pressed) cymbals except for the Zildjian Custom K Splash which is my pride and joy. The ATM10 does an excellent job suspended over the cymbals but I wish I had another mic for the kick drum. Recently bought a flash ($55) microphone cable to replace the hand-soldered dodgy one I was using and you wouldn't believe the improvement in sound quality - highly recommended.
When composing I start with a rhythm - from either drums or lyrics - then find the tune comes quite easily and naturally. I have a heap of tracks half recorded which I will upload once they have enough polish ... I know what you're thinking! :-)