The website of Rick Anderson KE3IJ is one of my favorites as it is filled with simple circuits, mainly simple receivers, that can easily be reproduced and that work well. See http://www.ke3ij.com/radios.htm. What I like is that on many pages there are little extra bits of circuitry that can be used in other projects too. Lke me, Rick loves the humble 2N3904 transistor which is useful from audio to VHF. They appear all over the place in his novel circuits.