In the current issue (May) of Everyday Practical Electronics they're giving away a CD containing the best of their Circuit Surgery columns.
http://www.epemag.wimborne.co.uk/
I've pasted a selection of what's covered below (there's loads more). For £3.10 you'd be mad not to get it!
US transistor substitutes, low Voltage NE555, Sound levels and Decibels, Op.amps 101, "Teach-In" amplifiers, Potential dividers and the 10% Rule, Op.amps -electrical ratings, Op.amps - signal handling, Conventional Current Flow, Op.amps - getting loaded. Biased approach, Surface mount selection, Op.amps - outputs and short circuit protection, A constructor's guide to methodical faultfinding, Ferric disposal. Testing transistors the quick and easy way, PCB track widths.
Switched mode power Supplies, Introduction to PLLs, Impedance matching, PCB solvents, Heatsink calculations: thermal resistances, Wiring transistors in parallel,Transconductance amplifiers, Un-confusing fuses. Electrolytic capacitors unravelled, Darlington transistors, All about MOSFETs, How to read circuit diagrams. CMOS op.amp solutions.
Digital timing without glitches etc...