http://www.nexusmods.com/oblivion/mods/35230 is an excellent pictured guide for Wrye Bash. Although, the guide seems to be somewhat outdated, but most features still exist and are useful to learn how to use them.
Also, make sure to install the latest stable Wrye Bash (the last link in this http://www.gamesas.com/topic/1612572-wrye-bash-thread-112/#entry25268144) and check that thread for futher updates.
As for good mods I would recommend anything from these mod collections along with a couple of other good mods.
http://afkmods.iguanadons.net/index.php?/topic/3024-relzbetawipz-arthmoors-collection/ (especially Alternative Beginnings, VERY popular)
http://lovkullen.net/Emma/oblivionbyemma.htm (especially Companion Vilja, VERY popular)
http://www.nexusmods.com/oblivion/mods/searchresults/?quicksrc_name=File+name&quicksrc_auth=TheNiceOne&quicksrc_game=101 (Dynamic Maps is a must have mod)
http://www.theassimilationlab.com/forums/topic/15105-relz-oblivion-xp/ (requires Kyoma's http://www.nexusmods.com/oblivion/mods/32200 and shadeMe's http://www.nexusmods.com/oblivion/mods/26510 for troubleshooting)
http://www.theassimilationlab.com/forums/topic/14882-relz-weather-all-natural/ (AndalayBay took over after Arthmoor had retired from Oblivion modding)
http://www.nexusmods.com/oblivion/mods/21862 (must have mod)
http://www.theassimilationlab.com/forums/topic/14793-relz-cobl/ (updated overhaul)
http://www.theassimilationlab.com/forums/topic/14830-relz-elsweyr-anequina/ (Iliana released an updated version before retiring from modding)
http://www.nexusmods.com/oblivion/mods/11280 (I recommend to install it via http://www.nexusmods.com/oblivion/mods/32277)
I may have forgot a mod or two.