I have two questions regarding site maps:
1) Currently my site has around 5,000 pages. However, in the future it will contain more than 50,000 pages. Should I start using sitemap-index with only one sitemap listed at the current time? Or should I use a sitemap and when I pass the 50,000 limit add a sitemap-index file with 2 sitemaps listed? Does it even matter??
2) Should I re-submit sitemap through Google webmasters tools every time I add a new URL? Or does it check it automatically?