How do blocks signal whether it supports segwit for the 95% threshold? Ideally, I'd also like to see graphs that indicate how close we are to segwit adoption and the number of minimum blocks we are away from actual segwit adoption.
BIP141 – Deployment says:

This BIP will be deployed by &quot;version bits&quot; BIP9 with the name &quot;segwit&quot; and using bit 1.
For Bitcoin mainnet, the BIP9 starttime will be midnight 15 november 2016 UTC (Epoch timestamp 1479168000) and BIP9 timeout will be midnight 15 november 2017 UTC (Epoch timestamp 1510704000).

As we're currently on the second version of blocks, the version field will be showing 0x20000002 when signaling readiness for segwit and 0x20000000 when not. Readiness for segwit2x would show as 0x20000010 if only signaling bit 4 or 0x20000012 if signaling both bit 1 and bit 4.
BIP 9 requires 95% readiness signaled over one difficulty period (from reset to reset). Once that is achieved, SegWit will be activated on the network after the following difficulty period has passed.
It appears that Coin.Dance will show support in the linked graph, as indicated by the footnote &quot;BIP 141 (voting starts on 2016-11-15)&quot;.
Note: In BIP9 signaling readiness only starts with the first difficulty retarget after the starttime. In the case of SegWit this is likely to be around the 19th of November.