Here are some links which can be of some help in your preparation for IAS Mains :

1. General Studies Book
   
2. IAS 2007 GENERAL STUDIES I
   
3. IAS 2007 GS II
   
4. IAS MAIN - 2007 History I
   
5. IAS 2007 Mains History II
   
6. UPSC: IAS 2007 ESSAY
   
7. Public Administration - 1998
   
8. 1997 IAS Pub. Admn. Mains Paper
   
9. 1998 IAS Pub. Admn. Mains Paper
   
10. 1999 IAS Pub. Admn. Mains Paper
    
11. 2000 IAS Pub. Admn. Mains Paper
    
12. 2001 IAS Pub Admn. Mains Paper
    
13. 2002 IAS Pub. Admn. Mains Paper
    
14. 2003 IAS Pub. Admn. Mains Paper
    
15. 2005 IAS Pub Admn Mains Paper
    
16. 2006 IAS Pub Admn Mains Paper
    
17. 2007 IAS Pub Admn Paper I
    
18. 2007 IAS Pub Admn Paper II
    
19. IAS Essay Compulsary : Eleven Years Paper
    
20. Some Cool Links for GS of IAS, RAS and other Exams
    
21. English Compulsory - Civil Services Examination - 2002
    
22. ENGLISH 2000 IAS Mains Paper
    
23. English Compulsory Civil Services Examination 2002
    
24. Collection of Epaper Links
    
25. Important Topics in Polity for GS
    
26. Imp. Topics in Ancient History
    
27. Imp Topics in Medieval History
    
28. Imp. Topics in Modern History
    
29. Imp. Topics in Economics