"It's been a long week but its time to get on with the football side of things and get back to basics on the training ground," said the youngster, speaking to readingfc.co.uk.
The highly-rated 20-year-old, who has played for England Under 20s, admitted it was a wrench to leave Arsenal after eleven years with the Gunners.
"I feel sad to leave Arsenal as I've been there since I was nine and it will always be a part of me. But now I feel I can pursue other avenues at Reading.
"You have to be realistic as it's difficult to break into the Arsenal team, and before I left the Gunners I spoke to Arsene Wenger who said he didn't want me to leave and that there was a contract waiting for me, but I decided to pursue another option with Reading and hopefully we'll be in the Premiership very soon."
Sidwell, who is expected to make his debut against Leicester next week, appeared in an Arsenal first team shirt nine times.