Components

[Milit]

Hi, i'm new to building stompboxes but wanted to give it a try. anyways, i was looking at this one here:
http://www.generalguitargadgets.com/index.php?option=content&task=view&id=90&Itemid=118

if you take a look at the bill of materials, there are several different capacitors and such listed.
So i found my way to maplins site, and ther seem to be loads of different types available.

http://www.maplin.co.uk/search.aspx?MenuNo=27&MenuName=Capacitors&FromMenu=y&criteria=Capacitors&doy=7m2&worldid=3&WM=Y&SD=N

is it necessary to use any particular type of capacitor? i'm confused 

[gtrmac]

Metalized Film types for values up to .1uf, a Tantalum is listed for the .22uf, and Electrolytic for the values 1uf and higher.  Most Electrolytics are polarized so you need to orient them correctly in the circuit. There is a Non-polarized 1uf 50 volt Electrolytic listed also.