Whenever I plan to build a pedal I make a stock list in excel first. I've even made a nice excel sheet with the parts I'm most likely ever to buy from my favorite webshops which includes their prices. I can enter whatever I need and it calculates what it will cost me, including shipping, in euros. It has almost all the resistors, caps, pots, enclosures and diodes stocked by Newtone and Musikding, and the most likely switches, trannies and IC's I've encountered in my builds so far. If you want it, send me a PM.
Anyway, based on what I ordered most in my old stocklists I've compiled a list of the most likely things you will probably have to order and which are worth stocking up on.
Ceramic caps:
47pf
100pf
220pf
330pf
470pf
680pf
Film caps:
1 nf
2,2 nF
3,3 nf
6,8 nf
10 nF22 nF
47 nF0,1 uF
0,22 uF0,47 uF
1uf
Electrolytics:
1uf
2,2uf
4,7uf
22uf
47uf
100uf
220uf
Resistors:
100R
120R
220R
470R
1K1,5K
2K
2,2K (my favorite value for LED's)
2,7K
3,3K
3,9K
4,7K
5,1K
5,6K
6,8K
8,2K
10K12K
22K
33K
47K
56K
68K
100K120K
220K
330K
390K
470K
680K
1M2,2M
Diodes:
1N4001
1N914
1N4148
1N5817
1N34A
9,1v zener
Pots:
10Kb
50Kb
100Kb250Kb
100Ka250Ka
500Ka
1Ma
1Kc
Trannies:
2N2222A
2N2907A
2N3904
2N5088
2N5089
2N5457
BS170
J201
MPSA18
IC's:
TC104SCP (Madbean seems to love them)
TL062
TL072TL074
RC4558Miscellaneous:
3PDT switchDPDT switch
DPDT on/on/on toggle switch
DPDT on/off/on toggle switch
SPDT on/on toggle switch
9volt DC jack9volt battery clip (for those who still use them, not I that is)
stereo jacks
mono jacks
5mm LED bezel Your favorite color in LED's (I prefer blue over red, red tends to become difficult to see on stage when the light engineer goes berserk)
125B enclosure (screw the 1590B! Overrated piece of junk)
1590BB enclosure for bigger builds
Your choice in knobs Solder!!!Anything marked in bold you should probably get twice as many as these get really used A LOT! Also keep in mind that the biggest part of your build cost will be the enclosure, the 3PDT switch, the jacks, pots and the knobs. A military saying has it that amateurs talk tactics while professional talk logistics, which translated to pedals means its nice to have all the caps and resistors you want, what will really limit how much and when you can build however is the other stuff.
Any chance you come across a bulk offer, get them, cause these things are easily between 3/5 and 3/4 of your total costs. You come across a nice pedal layout, you better have these in stock as well or you will still be waiting for your order to arrive instead of building right away as you probably want too. I ordered 2 lots of 10 Marshall style knobs each from eBay, they lasted me less then a month. I'm still waiting for a lot of 50 knobs and 20 3PDT switches to arrive, and I'm going to order at least 10 125B's next month.
Edit: I forgot, if you're going to order some vero stripboard, get it here:
http://www.bitsbox.co.uk/hardware.htmlBest vero stripboard I've EVER had the pleasure to work with. It looks less coppery then usual and makes the solder flow really nice and adhere easy to the board.